Eric Posner,"The U.S. Has No Legal Basis to Intervene in Syria"
Inter arma enim silent leges, said the Romans—in times of war, the law falls silent. But ours is a chattier society. Rather than keep silent, our laws speak loudly about war. We just don’t follow them—as the U.S. military intervention in Syria is about to show.
Press reports say that President Obama has ordered his lawyers to supply him with a legal justification for a military assault on Syria, and unnamed officials have cited the Geneva Protocol, the Chemical Weapons Convention, the Kosovo precedent, and the so-called Responsibility to Protect doctrine. They have not cited the United Nations Charter, which flatly bans military interventions without Security Council approval, which the United States cannot obtain because of Russian and Chinese opposition.
The Geneva Protocol of 1925 (which Syria ratified) and the Chemical Weapons Convention of 1993 (which Syria has not ratified) ban the use of chemical weapons, but do not authorize countries to attack other countries that violate these treaties. The United States has no more authority to attack Syria for violating these treaties than it does to bomb Europe for giving import preferences to Caribbean banana producers in violation of international trade law. At one time, countries could use military force as “countermeasures” against treaty violators, but only against violators that harmed the country in question—and Syria has not used chemical weapons against the United States—but in any event, that rule has been superseded by the U.N. Charter.