Between 2004 and early 2015, conflict between the Republic of Yemen Government (RoYG) and Al Houthi opposition forces in the north and between Al Qaeda-affiliated groups and RoYG forces in the south, forced people in northern Yemen to repeatedly flee their homes, resulting in the need for humanitarian aid. At the same time, fighting between RoYG forces and tribal and militant groups since 2011 limited the capacity of the RoYG to provide basic services, and humanitarian needs increased among impoverished populations. In late March 2015, a coalition led by the Kingdom of Saudi Arabia began airstrikes on Al Houthi and allied forces to halt their southward expansion. The ongoing conflict has damaged public infrastructure, interrupted essential services, displaced populations, and reduced the level of commercial imports to a fraction of the levels required to sustain the Yemeni population. The country relies on imports for 90 percent of its grain and other food sources. The escalated conflict, coupled with protracted political instability, the resulting economic crisis, rising fuel and food prices, and high unemployment, has left nearly 19 million people in need of humanitarian aid, and has put more than 17 million people at risk of starvation.