The U.S. and NATO could have shortened the fighting and removed the Assad regime’s threat, as they did in the 2011 Libya intervention. At the outset of the Syrian civil war, the rebels enjoyed significant gains in territory and population despite their lack of air, armor, and centralized command, and their dependence on light-infantry units. The Assad regime succeeded in halting the rebels’ momentum by relying on heavy armor, artillery, and air supremacy. Western imposition of a no-fly zone, combined with military aid to the rebels, could have blunted the regime’s advantages and allowed the popular uprising to succeed.
For the last two years, Russia and China have systematically protected Assad by vetoing proposals in the U.N. Security Council to impose heavy sanctions. Since the outbreak of the civil war, Russia has delivered heavy arms to Syria such as air and naval defense systems, large stocks of ammunition, aerial missiles and bombs, and perhaps helicopters and aircraft. While the U.S. and its NATO allies imposed arms embargos on Damascus and declared that Assad should step down, they limited their support for the rebels to non-lethal economic and humanitarian aid. Regional powers have filled the vacuum, with Saudi Arabia and Qatar apparently providing arms and funds to the rebels.
Mistaken worries about international law have kept the Western democracies, led by the United States, from stepping in to restore stability and prevent the further massacre of civilians. According to reports in the Wall Street Journal
, the Obama administration refused to send any direct military aid — not to mention taking more aggressive steps such as attacking Syrian air-defense units — because administration lawyers argued that the lack of U.N. Security Council authorization renders any U.S. aid illegal. While an international agreement, the Chemical Weapons Convention, bars the production of chemical weapons, Syria has not joined the treaty, and the law does not permit the use of force as a sanction.
Defenders of the administration might argue that fealty to the U.N. avoids any wider great-power conflict. U.N. Security Council approval of the Libyan intervention implied that neither Russia nor China would attempt to block Western attacks on the Qaddafi regime. Without such a guarantee, U.S. military aid or action in Syria might risk direct conflict with other countries: Syria and Iran might respond to U.S. force by launching attacks on Turkey and Israel to impose higher costs on the West. Russia might counter a NATO no-fly zone by sending sophisticated ground-to-air defense systems to Assad. Moscow might arm Damascus with top-shelf anti-ship missiles to hamper U.S. naval operations in the Eastern Mediterranean. Russia and China might send ships carrying arms, or Iran might continue its airborne aid, risking direct military conflict with U.S. forces. The risk of escalating the Syrian civil war into a broader conflict involving the great powers — which could end the long peace that has prevailed since 1945 — could far outweigh the gains of replacing Assad with a regime that respects the human rights of its population and disavows a revisionist agenda toward its neighbors.
Nevertheless, the more concrete benefits of removing the Assad regime outweigh the more speculative harms of Russian or Chinese resistance or great-power conflict. This calculation turns on both the costs of using force and the likelihood of Russian or Chinese military hostility, since the benefit of a peaceful Syria and the harm of a great-power conflict can be estimated and will not change under different scenarios.