Yemen is the fourth Middle East conflict zone where Iran has applied the Hezbollah model successfully to effectively take over the country. Iran has supported the Houthi rebelsa Shi’ite Muslim armed religious and political movement—since they launched a series of bloody insurgencies against the Yemeni government in 2004, culminating in the removal from power of President Abd Rabbuh Mansour Hadi, a key U.S. counterterrorism ally, in 2015.

Although the Houthis and their Ansar Allah movement identify with Zaidi Shi’ism, as opposed to the twelver Jaafari Shiism propagated by Iran’s revolutionary regime, Iran has obligingly backed the Houthis due to their opposition to the U.S.-led regional order and Saudi-backed Hadi government. The Houthi slogan “God is great/ Death to America/ Death to Israel /God curse the Jews/ Victory to Islam,” emulates the Iranian regime’s own “Death to America” motto and extremist ideology, underscoring the group’s links to Tehran.

The Houthis ideological affinity for Iran and role in the Islamic Republic’s hegemonic project were articulated publicly in October 2014, a month after the Houthi rebels captured Yemen’s capital city, Sanaa. Supreme Leader Khamenei’s chief foreign affairs advisor, Ali Akbar Velayati, proclaimed Iran’s support for the Houthis, saying “Ansar Allah brought about a transformation in Yemen which is unique in the history of this country and Ansar Allah’s consecutive victories prove that everything is based on an organized plan,” in a meeting with Zaidi scholars. Velayati went on to link the Houthi struggle in Yemen to that of other proxy forces around the Middle East fighting on behalf of Iran’s regional agenda, saying, “The Islamic Republic supports Ansar Allah as it sees the movement in line with the materialization of a part of the Islamic awakening. In some countries Islamic Awakening movements started but they faced defeats, however we are hopeful that they will gain success soon and the Islamic awakening will spread worldwide and the Islamic world will overcome its enemies and the Zionists.” The Zaidi scholars in attendance pledged their devotion to Supreme Leader Khamenei, stating that they view him as the leader not just of Iran, but of the entire Islamic world.

Iranian ties to the Houthis range from monetary and religious-based support to frequent shipment of arms and military training. A confidential 2015 U.N. report exposed clandestine Iranian efforts to ship arms to the group dating back to 2009. Iran’s provision of arms to the Houthis has only escalated since the group overthrew President Hadi in 2015. The Iran-backed rebels twice targeted a U.S. ship in the Persian Gulf in October 2016, and in November 2017 launched a ballistic missile targeting Riyadh’s international airport, indicating that Iran is helping the rebels acquire increasingly sophisticated weaponry. Iran’s support has helped the Houthis overcome some core deficiencies, including strategic planning, political mobilization, and operating advanced weaponry.

Iran is reportedly injecting Shi’a mercenary forces into the Yemen conflict, mirroring its strategy in Syria. According to a Reuters report, “Iranian and regional sources said Tehran was providing Afghan and Shi‘ite Arab specialists to train Houthi units and act as logistical advisers. These included Afghans who had fought in Syria under Qods Force commanders.” Also similar to Syria, Iran has outsourced many of its activities in Yemen to Hezbollah, which “remains the contact point between the two countries, the one running trainings and ‘building capacity’ for the Houthis, and the one directly running the Yemen file for Iran.”

Iran’s aid to its Houthi proxies has provided a low-risk, cost-effective avenue to becoming the dominant political and military influence in Yemen. Iran has also managed to weaken its geopolitical adversaries by goading an Arab coalition spearheaded by Saudi Arabia and the United Arab Emirates into the conflict, which has devolved into a costly war of attrition for their side. Yemen, meanwhile, has borne the brunt of this proxy war as the situation has emerged into one of the world’s most urgent humanitarian crises.