In the wake of the Arab Spring in 2011, the armed opposition Sunni rebel groups rose to overthrow the Shia-led Assad regime. Syria has become one of the most contested theaters of proxy war in the Middle East. To control Syrian military camps close to the Mediterranean Sea, Russia backed the Assad regime. Out of strategic concern for the Shia Crescent, Iran also chose to back Assad. Taking sides with the rebel groups are the United States, Saudi Arabia, Turkey, and the Syrian Kurds. The civil war has lasted over a decade, leaving behind a death toll exceeding 380,000 and more than 200,000 missing. The war continues to rage on.