Yemen’s civil war began in 2014 when Houthi insurgents—Shiite rebels with links to Iran and a history of rising up against the Sunni government—took control of Yemen’s capital and largest city, Sana’a, demanding lower fuel prices and a new government. Following failed negotiations, the rebels seized the presidential palace in January 2015, leading President Abd Rabbu Mansour Hadi and his government to resign. Beginning in March 2015, a coalition of Gulf states led by Saudi Arabia launched a campaign of economic isolation and air strikes against the Houthi insurgents, with U.S. logistical and intelligence support.
Hadi rescinded his resignation and returned to Aden in September 2015, and fighting has continued since. A UN effort to broker peace talks between allied Houthi rebels and the internationally recognized Yemeni government stalled in the summer of 2016. As of December 2017, Hadi has reportedly been residing in exile in Saudi Arabia.
In July 2016, the Houthis and the government of former President Ali Abdullah Saleh, ousted in 2011 after nearly thirty years in power, announced the formation of a “political council” to govern Sana’a and much of northern Yemen. However, in December 2017, Saleh broke with the Houthis and called for his followers to take up arms against them. Saleh was killed and his forces defeated within two days.
The intervention of regional powers in Yemen’s conflict, including Iran and Gulf states led by Saudi Arabia, threatens to draw the country into the broader Sunni-Shia divide. Numerous Iranian weapons shipments to Houthi rebels have been intercepted in the Gulf of Aden by a Saudi naval blockade in place since April 2015. In response, Iran has dispatched its own naval convoy, which further risks military escalation between the two countries.
In February 2021, Houthi rebels launched an offensive to seize Marib, the last stronghold of Yemen’s internationally recognized government, and in early March, Houthi rebels conducted missile airstrikes in Saudi Arabia, including targeting oil tankers and facilities and international airports. The Saudi-led coalition responded to the increase of attacks with airstrikes targeting Sana’a, Yemen’s capital. The offensive was the deadliest clash since 2018, killing hundreds of fighters and complicating peace processes.
Meanwhile, the conflict continues to take a heavy toll on Yemeni civilians, making Yemen the world’s worst humanitarian crisis. The UN estimates that 60 percent of the estimated 377,000 deaths in Yemen since 2015 are the result of indirect causes like food insecurity and lack of accessible health services. Nearly 74 percent, or twenty-five million Yemenis, remain in need of assistance. Five million are at risk of famine, and a cholera outbreak has affected over one million people. All sides of the conflict are reported to have violated human rights and international humanitarian law.
An economic crisis continues to compound the ongoing humanitarian crisis in Yemen. In late 2019, the conflict led to the splintering of the economy into two broad economic zones under territories controlled by the Houthis and the Saudi-backed government. In the fall of 2021, the sharp depreciation of Yemen’s currency, particularly in government-controlled areas, significantly reduced people’s purchasing power and pushed many basic necessities even further out of reach, leading to widespread protests across cities in southern Yemen. Security forces forcefully responded to the protests.
Separate from the ongoing civil war, the United States is suspected of continuing counterterrorism operations in Yemen, relying mainly on airstrikes to target al-Qaeda in the Arabian Peninsula (AQAP) and militants associated with the self-proclaimed Islamic State. In 2016, the United States conducted an estimated 35 strikes in Yemen; in 2017, it conducted about 130. In April 2016, the United States deployed a small team of forces to advise and assist Saudi-led troops to retake territory from AQAP. In January 2017, a U.S. Special Operations Forces raid in central Yemen killed one U.S. service member, several suspected AQAP-affiliated fighters, and an unknown number of Yemeni civilians.
The United States is deeply invested in combating terrorism and violent extremism in Yemen, having collaborated with the Yemeni government on counterterrorism since the bombing of the USS Cole in 2000. Since 2002, the United States has carried out nearly four hundred strikes in Yemen. While Houthi rebels do not pose a direct threat to the United States, their attacks on Saudi Arabian infrastructure and territory threaten an important U.S. partner.
Breaking from previous U.S. policy, U.S. President Joe Biden announced an end to U.S. support for Saudi-led offensive operations in Yemen in February 2021. The United States continues to send and sell weapons to countries in the region as a response to Houthi-led attacks. While the United States announced an end to supporting offensive operations, it has refrained from pushing Saudi Arabia to end a blockade on the coast of Yemen, which has prevented fuel tankers from entering Hodeidah, the main port and access point for humanitarian aid to flow into the country.
The Saudi-led coalition and the Iranian-backed Houthi rebels reached a UN-brokered cease-fire in April 2022; the cease-fire was renewed twice. Despite the official expiration of the cease-fire after six months, both sides have refrained from major escalatory actions.
Recent talks between Iran and Saudi Arabia in April 2023, mediated by China, have raised hopes of a political settlement to end the conflict in Yemen. The talks lead to a breakthrough agreement to re-establish diplomatic relations and re-open both sides' embassies after years of tension and hostility. Iran’s UN mission said that the agreement could accelerate efforts to renew the lapsed cease-fire.