In its continued effort to undermine the Houthi tribal movement in Yemen through force of arms, Saudi Arabia has managed to gather a growing alliance of Arab countries as well as logistical support from Turkey and the United States. Some have been surprised by the intervention's suddenness and the increasing ferocity of the air campaign, to which the number of Yemeni civilian casualties is a testament. Yet the latest military confrontation should not come as a surprise, since it occurs within the context of an eighty-year history of tensions between Riyadh and Yemen.
Within one year of Saudi Arabia's emergence as a unified state in 1932, the Kingdom of Yemen had already declared war against its northern neighbor over a border dispute. Upon receiving a Saudi peace delegation in 1933, Imam Yahya, the king at the time, famously derided Ibn Saud, the founder of Saudi Arabia, by saying, "Who is this Bedouin coming to challenge my family's 900-year rule?" During the ensuing war, the Saudi Bedouin army managed to capture the Yemeni coastal region of Asir and the northernmost provinces of Najran and Jizan, but it was forced to halt the offensive on the capital city of Sana because its troops could not navigate the north's difficult mountainous terrain. The subsequent 1934 peace accords, known as the Treaty of Taif, demarcated a border that granted Asir, Najran, and Jizan to Saudi Arabia. The contested status of these territories remains at the heart of Yemeni grievances today.
Initially, the signing of the treaty ushered in three decades of relative tranquility between the two countries, with their porous border frequented by traders and families from tribes that straddle both sides of the frontier. In 1962, however, the last Yemeni Imam, Muhammad al-Badr, was deposed and a Yemeni republic was founded, marking the beginning of a new era of tensions with the Saudis. The new republic's founders deemed the Treaty of Taif invalid and declared their intention to reconquer the three disputed provinces. These empty threats turned into serious fears when 70,000 Egyptian soldiers arrived to support the republic against a guerrilla opposition organized by Imam Badr and his loyal tribesmen. Saudi Arabia in turn supported the Badr camp through 1968 as the country descended into a bloody civil war.
When the war officially came to a close in 1970 following reconciliation between supporters of the republic and the imam, Riyadh recognized the state of North Yemen and offered a great deal of financial support. Fearing Moscow's influence in the area, the Saudis intended to "replace the Russian ruble with the Saudi riyal." Despite this support, however, various Yemeni leaders continued to refer to Asir, Najran, and Jizan as Yemeni territory.
Riyadh was willing to overlook this hostile rhetoric so long as the core principle of its grand strategy in Arabia was upheld -- namely, the Yemeni central government had to remain weak lest it challenge Saudi hegemony in the area. The Saudis were therefore alarmed when the northern and southern republics of Yemen declared a union in May 1990, forming a single state with a strong central government. At the time, however, Yemen's ill-prepared United Nations delegation happened to be cycling through the Security Council just as the United States was preparing to invade Saddam Hussein's Iraq. When this delegation voted against a UN resolution sanctioning military action against Iraq, Saudi Arabia reacted by immediately expelling hundreds of thousands of Yemeni migrant workers. The lost remittances and unemployed returnees imposed major socioeconomic problems on Yemen that continue to plague the country today.
In 1994, these economic woes and other factors pushed Yemen into a second period of civil war, this time between the southern separatist movement and the republic's government in the north. Viewing the conflict as an opportunity to reestablish influence over Yemen, Riyadh supported the southern government with munitions during the war and the north with increased aid after hostilities ended. The Saudis extended their influence over the government to such an extent that then-president Ali Abdullah Saleh was convinced to sign a treaty in 2000 reconfirming the borders demarcated by the Treaty of Taif. Various Yemeni opposition groups collectively known as the Asir Movement protested the manner in which this new accord was signed, in that it involved nearly $4 billion in bribes to local Yemeni sheikhs and government officials.
In addition to the spike in Saudi financial influence, the 1990s saw a sharp increase in Saudi Wahhabi and anti-Zaidi proselytizing in Yemen's northern highlands near the city of Sadah, an area dominated by followers of the Zaidi branch of Shia Islam. The present-day Houthi movement began then, as a collective effort to reeducate the northern tribes in Zaidi traditions and respond to threats from radical Wahhabis. Meanwhile, Saleh's acquiescence on the border issue and the increasing Saudi influence over Yemeni domestic politics became key Houthi grievances against the central government. After the movement's leader, Hussein al-Houthi, was killed in 2004, the tribes allied with the Houthi family began a protracted military struggle against the government. Realizing in 2009 that the movement presented a serious threat to the pro-Saudi leadership in Sana, Riyadh sent troops to fight the Houthis across the border with disastrous results, as over 130 ill-trained Saudi personnel were killed.
The current intervention, then, is rooted in growing Saudi alarm over the Houthi movement's popularity and the increasing strength of its tribal alliance. The Houthis' capture of Sana, rapid military expansion southward, and impending conquest of Aden despite foreign efforts to thwart their progress all present a serious threat to Riyadh's regional strategy -- especially as Houthi leaders have made no secret of their disdain and hostile intentions toward the Saudi monarchy. Alongside their military gains, the Houthis have emerged as a potential political force that can form a strong central government with an anti-Saudi agenda. For now, the Saudi coalition continues to gain the support of Arab and Western countries, several of whom seem to be on the verge of committing ground troops. This situation could further exacerbate the humanitarian crisis brought on by Houthi battles with multiple opposition groups and the expanding air campaign.
Riyadh and its coalition partners believe they are defending Yemen against an Iranian threat, and this view is not entirely unfounded given the Houthi movement's links to Iran (e.g., see PolicyWatch 2364, "Yemen's Zaidis: A Window for Iranian Influence"). Yet underlying the bombardments is a long history of Saudi-Yemeni tensions. Heeding the call of Saudi propaganda and fears over the security of the vital Bab al-Mandab Strait, the United States and other countries have been drawn into a local border war whose deep roots may not be fully appreciated.