With the support of the United States, Saudi Arabia, and the United Nations Security Council, President Hadi attempted to reform Yemen's political system. In early December 2017, the Houthi-Saleh alliance unraveled, culminating in the killing of former President Saleh on December 4, 2017. Nevertheless, Houthi forces remain ensconced in northern Yemen and remain in control of the capital. Access restrictions to certain areas of Yemen make it problematic for governments and aid agencies to count the war's casualties. One U.S. and European-funded organization, the Armed Conflict Location & Event Data Project (ACLED), estimates that 60,000 Yemenis have been killed since January 2016. Though fighting continues along several fronts, on December 13, 2018, Special Envoy of the United Nations Secretary-General for Yemen Martin Griffiths brokered a cease-fire centered on the besieged Red Sea port city of Hudaydah, Yemen's largest port. As part of the deal, the coalition and the Houthis agreed to redeploy their forces outside Hudaydah city and port. The United Nations agreed to chair a Redeployment Coordination Committee (RCC) to monitor the cease-fire and redeployment. On January 16, the United Nations Security Council (UNSCR) passed UNSCR 2452, which authorized (for a 6-month period) the creation of the United Nations Mission to support the Hudaydah Agreement (UNMHA), of which the RCC was a significant component. As of March 2019, the parties had made "significant progress towards an agreement to implement phase one of the redeployments of the Hudayda agreement." Since the signing of the Stockholm Agreement, the Saudi-led coalition has conducted airstrikes in Sanaa in retaliation for a Houthi drone attack against a Yemeni military parade. The Houthis took control of these missiles as part of their seizure of the capital. Yemen's Humanitarian Crisis

		Humanitarian Conditions and Assistance

According to the United Nations, Yemen's humanitarian crisis is the worst in the world, with close to 80% of Yemen's population of nearly 30 million needing some form of assistance. The U.N.Office for the Coordination of Humanitarian Affairs (OCHA) estimates that two-thirds of the population is food insecure, one-third are suffering from extreme levels of hunger, and 230 out of Yemen's 333 districts were at risk of famine as of January 2019. In sum, the United Nations notes that humanitarian assistance is "increasingly becoming the only lifeline for millions of Yemenis." Overall, the prospects for returning to a unified Yemen appear dim. According to the United Nations Panel of Experts on Yemen, "The authority of the legitimate Government of Yemen has now eroded to the point that it is doubtful whether it will ever be able to reunite Yemen as a single country."
This report provides information on the ongoing crisis in Yemen. Now in its fifth year, the war in Yemen shows no signs of abating. The war has killed thousands of Yemenis, including combatants as well as civilians, and has significantly damaged the country's infrastructure. The difficulty of accessing certain areas of Yemen has made it problematic for governments and aid agencies to count the war's casualties. One U.S. and European-funded organization, the Armed Conflict Location & Event Data Project (ACLED), estimates that 60,000 Yemenis have been killed since January 2016.
Though fighting continues along several fronts, on December 13, 2018, Special Envoy of the United Nations Secretary-General for Yemen Martin Griffiths brokered a cease-fire centered on the besieged Red Sea port city of Hudaydah, Yemen's largest port. As part of the deal, the coalition and the Houthis agreed to redeploy their forces outside Hudaydah city and port. The United Nations agreed to chair a Redeployment Coordination Committee (RCC) to monitor the cease-fire and redeployment. On January 16, the United Nations Security Council (UNSCR) passed UNSCR 2452, which authorized (for a six-month period) the creation of the United Nations Mission to support the Hudaydah Agreement (UNMHA), of which the RCC is a significant component. As of late March 2019, the Stockholm Agreement remains unfulfilled, although U.N. officials claim that the parties have made "significant progress towards an agreement to implement phase one of the redeployments of the Hudayda agreement."
Although both the Obama and Trump Administrations have called for a political solution to the conflict, the two sides in Yemen appear to fundamentally disagree over the framework for a potential political solution. The Saudi-led coalition demands that the Houthi militia disarm, relinquish its heavy weaponry (ballistic missiles and rockets), and return control of the capital, Sanaa, to the internationally recognized government of President Abdu Rabbu Mansour Hadi, who is in exile in Saudi Arabia. The coalition asserts that there remains international consensus for these demands, insisting that the conditions laid out in United Nations Security Council Resolution (UNSCR) 2216 (April 2015) should form the basis for a solution to the conflict. The Houthis reject UNSCR 2216 and seem determined to outlast their opponents while consolidating their control over northern Yemen. Since the December 2017 Houthi killing of former President Ali Abdullah Saleh, a former Houthi ally, there is no apparent single Yemeni rival to challenge Houthi rule in northern Yemen. Armed groups, including Islamist extremists, operate in other parts of the country, and rival political movements and trends advance competing visions for the long-term reestablishment of national governance in the country. The reconciliation of Yemeni factions and the redefinition of the country's political system, security sector, and social contract will likely require years of additional diplomatic engagement.
According to the United Nations, Yemen's humanitarian crisis is the worst in the world, with close to 80% of Yemen's population of nearly 30 million needing some form of assistance. Two-thirds of the population is considered food insecure; one-third is suffering from extreme levels of hunger; and the United Nations estimates that 230 out of Yemen's 333 districts are at risk of famine. In sum, the United Nations notes that humanitarian assistance is "increasingly becoming the only lifeline for millions of Yemenis."
For additional information on Yemen, including a summary of relevant legislation, please see CRS Report R45046, Congress and the War in Yemen: Oversight and Legislation 2015-2019, by Jeremy M. Sharp and Christopher M. Blanchard.