The Saudi-led military intervention into Yemen called ‘Operation Decisive Storm’ was announced on 26 March 2015 (renamed to ‘Operation Restoring Hope’ in April 2015). It came after a tumultuous period in Yemen following widespread protest in 2011/2012 that succeeded in forcing the long-time president Ali Abdullah Saleh to hand over the presidency to his vice president, Abdrabbuh Mansur Hadi. The subsequent transition process was initially accentuated by the United Nations (UN) as a positive example of a negotiated transfer and an inclusive political process, but gradually it became clear that it had failed to achieve buy-in from key elite actors. In September 2014, an armed group, commonly referred to as the Houthi movement, took control over the capital, Sana’a, and after a brief intermezzo where the UN sought to (re)commit the warring parties to political negotiations, the political process collapsed. The situation quickly escalated as Hadi and his government were placed under house arrest. In mid-February 2015, Hadi escaped from house arrest and travelled to Aden, the former capital of South Yemen, which he announced as his interim capital. However, within a month Aden was under attack from the Houthis and Hadi fled to Saudi Arabia. At this point, Hadi requested the UN and the Arab League for support by all available means including military intervention with reference to the UN Charter Article 51 and the right to self-defence, as well as the Charter of the Arab League and the Treaty on Joint Defence, in March 2015 just before the commencement of the Saudi-led military intervention.¹

In the announcement of the Saudi-led military intervention by the Saudi ambassador to the US, Adel al-Jubeir, the objective of the intervention was ‘to defend the legitimate government of President Hadi from the takeover attempts by the Houthi militia in Yemen’.² Although Saudi Arabia has a long history of interfering in Yemeni politics, the 2015 military intervention stands out for its intensity. Hence, researchers and analysts have discussed the reasons for this shift in Saudi foreign policy, pointing to a combination of internal Saudi politics and structural shifts following the Arab Uprisings including the deepening regional conflict between Saudi Arabia and Iran and American retrenchment from the region.³ This chapter will briefly outline the main arguments for the onset of the intervention as a starting point for an analysis of why Saudi Arabia at the time of writing has still not managed to terminate a military intervention that was intended to be short and limited. The literature on third-party involvement in intra-state conflicts has established that generally the duration and lethality of civil war increases with the involvement of third parties.⁴ The chapter then uses the notion of sunk cost effect which is manifested in a greater tendency to continue an endeavour once an investment in money, effort or reputation has been made, to argue that Saudi Arabia’s inability to extricate itself from the conflict in Yemen is a consequence of the material and reputational resources that Saudi Arabia has already spent in Yemen.⁵ The chapter proposes that the Saudi linkage of the Houthis to Iran framed the conflict as part of the broader rivalry between Iran and Saudi Arabia and that, as the conflict in Yemen has become increasingly complex, this has increased Saudi reputational and material cost related to withdrawal.

The Yemeni state formation process and regional interactions

There is a widespread misconception of Yemen as being exceptionally isolated.⁶ However, Yemen has a long history of being placed at the centre of regional rivalries as a result of the country’s geostrategic placement on the Arabian Peninsula. This section briefly shows how regional and international involvement in Yemen’s domestic affairs is not new. These examples also illustrate how, more than any other factor, it is Yemen’s proximity to Saudi Arabia that has defined how Yemen has been affected by regional trends, whereas Iran has historically had limited ties to Yemen. Moreover, whereas Saudi Arabia has sought to garner American support for its policies concerning Yemen, the US interest and thus influence on domestic Yemeni affairs has historically been limited.

Historically, northern Yemen was an Imamate where, although tribes held considerable independent power, there was a process following Ottoman withdrawal from Yemen to centralise power with the Imam. The Imamate was a Zaydi theocracy, characterised by autocratic rule, widespread poverty and inequalities.⁷ On 26 September 1962, a group of army officers, urban merchants and tribal leaders overthrew Imam Muhammad al-Badr, who had just taken power from his father, Imam Ahmad. Muhammad al-Badr managed to flee Sana’a and was able to rally tribal and Saudi support spurred by Nasser’s Egypt support to the republicans. Although the Egyptians had initially envisioned a limited short-term intervention, their engagement in Yemen quickly grew which resulted in around 70,000 Egyptian soldiers stationed in Yemen.⁸ The involvement of Saudi Arabia in the 1960s civil war was spurred on by a fear that if Egypt was victorious North Yemen would become a republican state hostile to Saudi Arabia and allow a regional enemy, Egypt, to gain a foothold on the Arabian Peninsula. According to Gregory Gause, the guiding principle of Saudi policy during this period was to seek the removal of Egyptian military presence in Yemen as it was perceived as a direct threat by the Saudi regime.⁹ The issue of the Imam being Zaydi was considered less important than the need to counter Egypt and maintain a royalist regime.¹⁰ This led Saudi Arabia to support the Zaydi monarchy to retain the status quo but at the same time, the Saudi focus on the Egyptian presence in Yemen and not the restoration of the Imamate complicated relations with the royalists.¹¹ This way, the civil war in Yemen became part of the cold war between Saudi-led Arab monarchies and Egypt-led Arab nationalists of the 1960s. The Saudi preference for stability was shared by key global powers at the time such as the British as well as the Iranian shah who saw the coup in Yemen as an element in growing Soviet influence in the region.¹² However, as noted by Banafsheh Keynoush, the relationship between Iran and Saudi Arabia was already at this point characterised by a certain Saudi apprehension about Iranian Shia influence due to Shia clerical efforts to politicise religion across the Gulf region and suspicions by Saudi Arabia of Iranian interference in the Eastern Province.¹³ The Saudis primarily supported the royalists with funds and smaller weapons, but not sophisticated military equipment or direct military intervention. In the end, the republicans prevailed in Yemen, but Egypt did not. Instead, Yemen drained Egyptian resources and weakened Nasser, but Egypt did not withdraw until 1967 following the defeat in the Six-Day War.¹⁴ In 1970 a national reconciliation formally ended the conflict and the Saudis recognised the Yemen Arab Republic (YAR). The YAR was weak and dependent on Saudi aid.¹⁵ The weakness of the state was further accentuated by the increased political and military role of the tribes who had benefitted from both Egyptian and Saudi weapons and patronage during the civil war. Saudi Arabia sustained direct payments to tribal actors following the end of the civil war and was thus able to extend considerable influence over the YAR.¹⁶

Saudi Arabia and Yemen share a long and fluid border. The fluidity has been formally integrated into the Treaty of Taif from 1934. The Treaty of Taif came about after a Saudi attack on the Imamate had made some headway, especially by capturing Hodeida, which had led the Imam to call for aid from European powers. The subsequent treaty saw Saudi Arabia withdraw from Yemen in exchange for the Imam’s recognition of Saudi sovereignty over Asir, Najran and Jizan, three border areas. In 2000, the Treaty of Jedda formally demarcated the current border. Key to these border agreements was that they recognised that the border would transect tribal territory and thus granted residents of the Yemeni–Saudi borderland on both sides the right to cross the border with limited restrictions. However, the Saudis have long seen the border as an Achilles heel that allowed illegal immigrants, al-Qaeda operatives as well as drug smugglers and gun runners access to Saudi Arabia. Consequently, Saudi Arabia began a process of demarcating the border which included building a physical barrier for fortification. The process has been slow due to tribal resistance, but in 2013 the Saudi government renewed its efforts as a consequence of the Houthis posing a growing threat in the area.¹⁷ This gradual militarising of the border was underlined in 2009 when Saudi Arabia intervened in the sixth Sa’ada war on the side of the Saleh regime. The Sa’ada wars, fought between 2004 and 2010, were the result of a gradual escalation of a conflict between Zaydi revivalists in northern Yemen and the Saleh regime.¹⁸ Increasingly, the conflict evolved to full-scale warfare as the Houthis, named after Hussein al-Houthi, who was killed by government forces during the first round of fighting in 2004, gained supporters, spurred on by undifferentiated repression of the entire northern Yemen by the Saleh regime.¹⁹ In 2009, the conflict was internationalised as Saudi Arabia allowed the Yemeni army to attack the Houthis from Saudi territory and itself carried out airstrikes in Yemen.²⁰ At this point, there was also an effort, spearheaded by Saleh, to frame the Houthis as an Iranian-backed group who sought to return the country to ‘the dark ages of the imamate’.²¹ However, at this time the Saudi involvement in Yemen was limited, and the narrative of the Houthis as being directed from Tehran failed to gain substantial traction internationally. Most notably, the US largely rejected the claim as the Yemeni regime was unable to back up its accusations with evidence.²² The Saudi military intervention was of much smaller scale than the current intervention and was quickly ended when it became clear that it did not have a deterring effect on the Houthis.

Explanations for Saudi-led military intervention into Yemen in 2015

Saudi Arabia has had a long history of intervening in Yemen, but the military intensity of the current intervention is historically unique. Indeed, as highlighted in the previous section, although Saudi Arabia has intervened militarily in Yemen before, the general pattern has been that Saudi Arabia has preferred to influence Yemen through support to domestic actors. Scholars and academics seeking to explain this break have tended to focus either on internal Saudi politics or the regional and international shifts following the perceived disengagement of the US from the region and the growing influence of Iran.²³

Domestically, Saudi Arabia was in a process of transition at the time of the commencement of the intervention in 2015. Although Saudi Arabia was not rocked by massive popular protests during the Arab Uprisings, the regime witnessed physical and virtual protests among both the Shia minority and the Sunni majority.²⁴ The largest protests were by Shia Muslims in the Eastern Province. These protests were met by a campaign of demonizing the Shia as criminals seeking to undermine national security on behalf of Iran and a violent crackdown by the regime.²⁵ However, there was growing bottom-up pressure for political reform and public sector improvements. In January 2015, King Abdullah bin Abdulaziz died and was replaced by King Salman. King Salman quickly began a process of positioning his son, Mohammad bin Salman (MbS), as his successor. In 2015, MbS was named defense minister, and later deputy Crown prince. In 2017, he officially became Crown prince and thus first in line to take power when the ailing King Salman dies.²⁶ Domestically, Saudi Arabia has seen an unprecedented centralisation of power in his hands.²⁷ At the same time, the ascent of MbS has resulted in a more assertive Saudi foreign policy of which the intervention in Yemen is the pre-eminent example. MbS is generally seen as the architect of the Saudi intervention in Yemen as he has sought to establish himself as a powerful leader both domestically and regionally.

Regional and international shifts, particularly the perceived disengagement of the US from the region, created concerns in Saudi Arabia that the US would no longer commit itself to upholding stability in the region. This shift facilitated a move towards a more aggressive foreign policy by Saudi Arabia and the UAE. Thus, the US retrenchment has led to a greater sense of ownership of their own security among the Gulf states.²⁸ Additionally, the signing of the nuclear deal, the Joint Comprehensive Plan of Action (JCPOA), in 2015 further exacerbated Saudi concerns that the US was no longer willing to invest in upholding regional order or countering Iran. Since President Donald Trump took office in 2017, the relationship between the US and Iran has gradually deteriorated as exemplified by the US decision to withdraw from the JCPOA in 2018. These tensions between Iran and the US have had effects on the war in Yemen. Most notably, the framing of the Houthis as an Iranian proxy has gained traction and negatively impacted the potential for political solutions and compromise.

The Saudi-led intervention in Yemen has the hallmarks of a ‘status-altering’ event.²⁹ These types of events are, according to Jonathan Renshon, public and dramatic enough to capture the attention of the international community. But the intervention should not be reduced to MbS’s desire to consolidate himself as the centre of power in Saudi Arabia, and Saudi Arabia as the central power in the region.³⁰ Renshon goes on to argue that during Egypt’s intervention in Yemen’s civil war in the 1960s, Nasser was unable to withdraw because ‘once his [Nasser’s] prestige was engaged, the costs of backing down and abandoning his Yemeni allies only grew’.³¹ However, the notion that the intervention increases Saudi prestige does not alone provide a convincing argument for a continued Saudi intervention. The intervention has led to the world’s current worst humanitarian disaster and although Saudi Arabia seeks to underscore its position as the largest contributor of aid to Yemen, the humanitarian consequences of the intervention, including numerous alleged unlawful airstrikes, have led to growing critique from the international community that strains Saudi Arabia’s international reputation.³²

More importantly, Saudi Arabia has long considered Yemen a real and existential security threat. This threat became more imminent with the security vacuum created by the uprising in 2011–2012 as it was feared that the conflict would spread across the border and destabilise Saudi Arabia or lead to an uptick in terrorist attacks.³³ Previously, Saudi Arabia had been able to extend some control over Yemeni politics through its extensive patronage network. However, by 2011 the network had been weakened which was further accelerated by the political vacuum following the uprising and subsequent transitional process. This left Saudi Arabia lacking means of influencing Yemeni elite actors. Saudi Arabia sought to use the vacuum created by the uprising and moved to control the transition in Yemen under a Gulf Cooperation Council (GCC) umbrella. The negotiated transfer of power from Ali Abdullah Saleh to his vice president, Abdrabbuh Mansur Hadi, prevented a short-term collapse of Yemen and secured Saudi Arabia substantial influence in domestic Yemeni politics. Hadi was from the onset dependent on external actors and thus amenable to Saudi influence. However, Hadi was not able to build internal legitimacy in Yemen and gradually frustrations grew with the lack of economic and public service improvements. Yemen became more and more unstable and as the Houthis’ military and political power grew, they increasingly posed a direct security threat to Saudi Arabia.

The Saudi-owned media and statements from Saudi officials rushed to identify the Houthis as Shia, and as a threat to not only Yemen but the entire region. This way the regionalisation of the conflict in Yemen became part of a broader trend in the aftermath of the 2011 uprisings to use sectarian narratives couched in anti-Iranian terms.³⁴ The Houthis were framed as a proxy of Iran which served as a key factor in legitimising and garnering international support for the intervention.³⁵ Saudi Arabia has especially sought to link the Houthis to a broader securitisation of an Iranian threat to the US which continues to attach strategic importance to the Gulf region. However, there is limited evidence pointing to substantial Iranian involvement in Yemen before 2015.³⁶ The Iranian leadership has denied having strong material ties with the Houthis. Yet, the feeling that Iran was gradually gaining a foothold on the Arabian Peninsula was troubling for Saudi Arabia at a time of rising Iranian power.³⁷ There seems to have been a genuine fear in Saudi Arabia that Iran was seeking to transform the Houthis into a Hezbollah-like fighting force. This would pose a substantial challenge for Saudi Arabia, especially in the border region. The intervention thus aimed at defeating the Houthis with a proven willingness to attack Saudi Arabia, while showing Iran that it would not accept a strong Iranian presence in Yemen. More generally, the intervention in Yemen demonstrated that Saudi Arabia is willing to take political risks and commit to substantial military intervention. The Saudi intervention in Yemen, framed as an intervention to save Yemen from Iran, was initially popular in Saudi Arabia and endorsed by Saudi Islamist forces across the spectrum.³⁸ This way, the intervention in Yemen initially did boost the domestic and regional profile of MbS but this effect has since waned.

Saudi Arabia’s inability to extricate from Yemen: Sectarianisation and regionalisation

Most existing literature on the Saudi-led military intervention has focused on the onset of the intervention, whereas fewer accounts have explored why Saudi Arabia has not been able to disengage from Yemen despite clear signs that Saudi Arabia would like to see an end to the conflict.³⁹ The short answer to the question of why Saudi Arabia has not ended the military intervention in Yemen is that the objectives of the campaign have not been achieved. Despite more than seven years of warfare, the military intervention has at the time of writing not been able to either restore Hadi or limit Iranian influence in Yemen. In fact, the opposite can be said to have happened. The ties between the Houthis and Iran have grown, and the fragmentation of Yemen left Hadi devoid of real decision-making power, culminating in his removal in 2022. The conflict in Yemen is part of a general trend where an unprecedented number of conflicts experience external involvement.⁴⁰ As already mentioned, external involvement has been shown to generally increase both conflict duration and lethality. This has been the case in Yemen where fatality numbers have increased as more external actors became involved and the complexity of the conflict increased.⁴¹ This section discusses how the increased complexity of the conflict has impacted the Saudi ability to withdraw from Yemen. First, the involvement of third parties changed the dynamics of the conflict. It went from being a containable civil war to a complex and multifaceted conflict with a total fragmentation of the Yemeni state. Second, the rhetorical framing of the Houthis as an Iranian proxy had the unintended side effect of leading to a strengthened relationship between the Houthis and Iran.

The involvement of the Saudi-led coalition increased the complexity of the conflict in Yemen in multiple ways. First, the ability of Saudi Arabia to extricate itself from the conflict has been affected by the gradual undermining of Hadi. This has, arguably, been brought to the fore by the actions of the Saudi-led coalition’s second largest actor, the UAE. The Saudi-led coalition initially consisted of ten countries but several of these have been contributors more on paper than reality and several others such as Qatar and Morocco are no longer part of the coalition.⁴² The UAE has contributed substantially to the intervention but has opted to develop capabilities on the ground in southern Yemen. Although the UAE has scaled back its contribution in Yemen, it remains a major player in the south of Yemen where it pursues its own geopolitical and economic interests.⁴³ The UAE has focused on gaining control of energy infrastructure and commercial ports in concordance with a broader strategy for control over the important sea passage, Bab al-Mandeb, that separates Yemen and the Horn of Africa. As part of this strategy, the UAE has supported secessionist forces that allows it substantial influence in southern Yemen but this has also, on occasion, put the UAE in a direct collision course with Saudi Arabia, particularly when it viewed Hadi as the legitimate president.⁴⁴ There were direct confrontations between the Saudi-backed Hadi government and UAE-backed secessionists, most notably the Southern Transitional Council (STC). The STC continued to challenge the Hadi government’s hold over southern Yemen, which during the spring of 2020 escalated when the STC declared a state of emergency and self-administration across southern Yemen.⁴⁵ The increasingly independent and occasionally directly confrontational policy of the UAE introduced a level of uncertainty into the conflict. It complicated mediation efforts as the unstable position of Hadi had been accentuated while raising questions about the relative balance of power in the coalition in Yemen. Thus, the fragmentation of the coalition detracts from the overall conflict with the Houthis and has given the Houthis an incentive to prolong the conflict in the hopes that the coalition will gradually fall apart.⁴⁶

Second, the linkage of the Yemen conflict to the regional rivalry between Iran and Saudi Arabia has exacerbated cleavages and provides incentives for parties in the conflict to escalate instead of seeking domestically anchored settlements. The Saudi military intervention in Yemen was legitimised through the reference to the call for assistance by all means necessary under Article 51 by the internationally recognised president Hadi as well as the Saudi right to self-defence. In the process, there was a securitisation of the Houthis as presenting a threat to the Yemeni people, Saudi Arabia and regional as well as international security. Contrary to during the Sa’ada wars in 2004–2010, Saudi Arabia has been successful in framing the conflict in Yemen as part of a wider confrontation between Sunnis and Shia and the Houthis as an Iranian proxy. First, although the religious divide between Sunni and Shia Islam has traditionally not been important in Yemen, the conflict lends itself to a sectarian framing because the Houthis mainly adhere to the Zaydi religious tradition. The Zaydis make up approximately 35 per cent of Yemen’s population and are centred in the northern highlands, hence whereas not all Houthis are Zaydi, there is substantial overlap. However, Zaydism is distinct from the Twelver Shiism that is practised in Iran and the Houthis have not previously been strongly associated with Twelver Shiism. Yet, as argued by Rola El-Husseini, with the rise of sectarianism in the Middle East, the Houthis along with the Alawis of Syria became part of the Shia camp, a conceptual category referred to as ‘new Shi’a’.⁴⁷ Consequently, there has been a sectarianisation of the conflict.⁴⁸ Gradually, Yemeni actors including the Houthis have begun framing the conflict in sectarian terms instead of as a political battle.⁴⁹ Hence, as argued by Morten Valbjørn, whereas the real drivers of the conflict between Iran and Saudi Arabia have more to do with geopolitics than sectarianism, the Shia/Sunni schism was used rhetorically and in how actors have linked local proxies and regional allies.⁵⁰

There are strong indications that the Houthis have been developing a stronger relationship to Iran since the commencement of the Saudi-led military intervention into Yemen in 2015 as demonstrated by the reception of a senior Houthi official in Tehran by Iran’s Ayatollah Khamenei in July 2019.⁵¹ Yet, the relationship between the Houthis and Iran is better explained by a broader focus on ideological commonality than a narrow fixation on doctrinal belief. Iran and the Houthis share opposition to the US and its allies such as Israel and Saudi Arabia, as well as a general focus on anti-imperialism.⁵² The complex drone attack on the Saudi Arabian oil-processing facilities Abqaiq and Khurais on 14 September 2019 that impacted global oil prices serves as an example of how the same event can be interpreted differently. The Houthis took responsibility for the attack, but strong doubts have been raised about Yemen as the place of origin for the drones. Regardless of the geographical origin of the attacks, Iran is widely believed to be the mastermind of the attacks, a position that has been officially furthered by the US.⁵³ In this narrative, the Houthi willingness to accept responsibility for the attack is interpreted as proof of a strong Houthi–Iran proxy relationship.⁵⁴ However, a more compelling explanation is that the Houthis’ involvement in the Aramco attacks stemmed from a calculation that it would serve their organisational goals. The Houthis have little fear of retribution from Saudi Arabia. On the contrary, when the Houthis argue that the strikes were in retaliation to the air strikes carried out in Yemen, it appeals to their core audiences in Yemen. The Houthis want to be seen as able to strike back and threaten the security of Saudi Arabia.⁵⁵ In addition to appealing to core audiences internally, another advantage could be to strike fear in domestic enemies as well as Saudi Arabia which could strengthen their bargaining position in future peace negotiations. Overall, the Saudi focus on the link between the Houthis and Iran seems to have had the unintended effect of pushing the Houthis closer to Iran.

Consequences for the Saudi ability to withdraw: The notion of sunk cost

Whereas the sectarianisation and regionalisation of the conflict helped Saudi Arabia garner international support or at least acquiescence for its intervention into Yemen, the lack of a strategy for how to de-securitise the Houthis has subsequently challenged Saudi Arabia’s ability to terminate the intervention. The sunk cost effect refers to a tendency to continue an endeavour once an initial investment has been made, in part because the estimation of likelihood of success becomes inflated. Thus, once an actor has invested in a course of action, the actor is more likely to continue that course even if it will lead to further costs because of an aversion against accepting the initial investment as a loss.

The Saudi-led military intervention in Yemen has led to a complete fragmentation of Yemen and although Iran has historically had limited interest in Yemen, the relationship between the Houthis and Iran has grown since the commencement of the Saudi-led military intervention. Iran has become the principal backer of the Houthis and although the direct support is likely marginal for the Houthis’ domestic endeavours, documentation of Iranian support has increased. However, Iran’s interest in Yemen remains limited and primarily bound to the importance attached to Yemen by Saudi Arabia.⁵⁶ While the Houthis are unlikely to take direction from Iran that does not benefit their interests or align with existing priorities, the fact Iran is their only viable patron has led to a situation where the help Iran is able to provide goes a long way in assuring leverage.⁵⁷ According to the UN Panel of Experts on Yemen, the trend has been for the Houthis to deploy their most sophisticated, longer-range uncrewed aerial vehicles and land attack cruise for attacks on Saudi Arabia.⁵⁸ It is suggested that the missiles provided by Iran are smuggled into Yemen in pieces that are then welded together inside Yemen, and that Iran has provided the Houthis with training and technical assistance.⁵⁹ Overall, Iran seems to view the relationship to the Houthis as a low-cost opportunity to antagonise Saudi Arabia, while accepting limited ability to control domestic Yemeni politics. It is the shared animosity against Saudi Arabia that has facilitated and shaped the relationship. This is most clearly demonstrated by the fact that the Houthis have been able to not only sustain but to expand their campaign of military operations against Saudi Arabia. Consequently, the Saudis cannot convincingly claim that the intervention has successfully weakened the Houthis or limited Iranian influence in Yemen. According to the psychology of sunk cost this would lead Saudi Arabia to struggle to withdraw from its intervention. The sunk cost effect is manifested in a greater tendency to continue an endeavour once an investment in money, effort or time has been made. The idea is that the sacrifices already made will be rendered void if the military intervention is not completed.⁶⁰ The psychological barrier to withdrawal and compromise thus increases with the resources allocated to the intervention in the first place. In the Saudi case, a withdrawal now, after more than seven years of intervention, when the impact of Iran is arguably greater than at any other time in Yemeni history and the internationally recognised President Hadi is no longer relevant, would certainly be hard to frame as a victory or military success that could justify the intervention to begin with. Hence, as demonstrated by the notion of sunk cost, Saudi Arabia struggles to withdraw from Yemen. The regionalisation of the conflict that helped Saudi Arabia gain international support for the commencement of the conflict is now making termination of the conflict more complicated.⁶¹ Iran, on the other hand, was linked to the Houthis before there was any substantial relationship and has thus been able, with limited investments, to project an image of Yemen as being part of its extensive network of allies. Iran has seized the opportunity to make political gains from the ability of the Houthis to withstand the Saudi-led military onslaught while it has avoided becoming so closely aligned with the Houthis that it had to substantially invest either material or reputational resources to the conflict.

The US tendency to defer Yemen-related questions to Saudi Arabia combined with the linkage of the Houthis to Iran meant that Saudi Arabia saw tacit support from the international community in the form of key a UN resolution, Resolution 2216, enacted in April 2015 to the intervention. It demands that the Houthis unconditionally withdraw from all seized areas, relinquish all arms seized from military and security institutions and refrain from provoking neighbouring states.⁶² Additionally, the US has augmented the Saudi-led campaign with logistical and intelligence support. Saudi Arabia has continuously referred to Resolution 2216 as the starting point for peace negotiations, whereas the Houthis unsurprisingly have rejected the terms for negotiations stipulated in the resolution. This has been one of the factors that has hindered the UN’s ability to effectively negotiate a peace deal. There have been indications that the Saudis were becoming more willing to compromise and had sought to bilaterally negotiate with the Houthis. In 2017, emails were leaked that indicated that MbS had told US officials that he wanted to leave Yemen.⁶³ However, the UN-led peace negotiations have struggled to gain traction and bilateral negotiations between the Houthis and Saudi Arabia have so far not yielded substantial results.⁶⁴ Saudi Arabia’s main priority is to keep itself safe. However, since 2015 the frequency and sophistication of the Houthis’ attacks on Saudi Arabia have increased. The uptick in attacks has been described as a warning from the Houthis to Saudi Arabia of their abilities and willingness to retribute if Saudi Arabia does not adopt a more conciliatory approach towards the Houthis. Saudi Arabia has in principle shown willingness to engage with the Houthis but demanded that they distance themselves from Iran.⁶⁵ The Saudi rhetoric that framed the Houthis as an Iranian-backed militia has been so effective that it is making it difficult for the Saudis to normalise political relations and engage in bilateral negotiations with the Houthis. This underlines how the Saudis were successful in the sectarianisation and securitisation of the Houthis, but have not had a strategy for the subsequent de-sectarianisation or de-securitisation of the conflict that would facilitate a move from military intervention to a normalisation of political processes.⁶⁶

Conclusion

Whereas the conflict in Yemen began as a detainable domestic political conflict, it has increasingly become regionalised while Yemen has fragmented. Hence, whereas it would be an oversimplification to call the conflict in Yemen a proxy war, the regional rivalry between Iran and Saudi Arabia has complicated and exacerbated matters. Saudi Arabia intervened in Yemen with the stated objective to reinstate the internationally recognised President Hadi and contain the growing Iranian influence. However, after more than seven years of military campaign, Saudi Arabia has failed to achieve its objectives. This chapter has discussed why Saudi Arabia has not been able to extricate itself from the military campaign in Yemen. It has argued that the effective rhetorical sectarianisation and securitisation of the Houthis have unintendedly increased the capacity of the Houthis by strengthening their ties to Iran, and left Saudi Arabia with a dilemma in terms of how to de-escalate and normalise relations with the Houthis while claiming the campaign as a victory. The war in Yemen has demonstrated Saudi Arabia’s capacity and willingness to sustain a years-long military campaign, but also its inability to use that campaign to achieve its political objectives. Saudi Arabia harbours a genuine fear of Iranian encirclement, which, in combination with the Houthis’ proven willingness and ability to target sites in Saudi Arabia, has left the Saudi leadership fearing the Houthis as an existential threat. The importance attached to Yemen by Iran is much more limited. Events in Yemen are not considered an existential threat to Iran, and consequently fewer resources have been delegated to Yemen. However, with the strong rhetorical linkage of the Houthis and Iran, Iran has been able to project a hand in Yemen despite not having diverted significant resources to the Houthis.⁶⁷

It has been argued that Iran has deliberately talked up its position in Yemen to be able to offer to withdraw from Yemen as a sign of compromise towards Saudi Arabia or even the US. This has led to the suggestion that the conflict in Yemen could prove an opportunity for Iranian–Saudi dialogue.⁶⁸ Despite persistent reports of bilateral talks, announcements of ceasefires and a Saudi desire to retract itself from the Yemen conflict, the war has not been terminated at the time of writing. Instead, Yemen remains caught in a conflict that has completely fragmented the country. The regionalisation of the conflict has not only impacted the severity and duration of the conflict, but also allowed the Houthis to frame it as one between them and Saudi Arabia. Consequently, peace negotiations have focused on a halt in the Saudi-led military campaign and the blockade while paying much less attention to the Yemeni resistance to the Houthis. It may be that a withdrawal of Saudi Arabia could throw Yemen into a full-blown civil war which could become even more bloody and contracted than the Saudi-led military intervention.