After the 911-terror attacks, people realized that terrorism posed a serious, global security threat. While the international community looked to counter terrorism through mechanisms and actions flowing from the Charter of the United Nations, resolutions of the Security Council, treaties and custom of international law, America launched military operations in Afghanistan and Iraq as part of its "war on terror"; discrepancies between the two approaches gave rise to controversies concerning the doctrines of self-defense and preemption in international law. Bush administration created a "gray zone" between the laws of war and international criminal law. Could prisoners detained in Guantanamo Bay be treated according to the rules of the Geneva Convention? Recently the Supreme Court of the U.S. passed judgments which applied the right of habeas corpus to war powers claimed by the president. Although the legal issues may not concern terrorism directly, the opinions of court nonetheless clearly have some role to play in clarifying the controversies surrounding international law regarding the war of terror.