In 2003, George W. Bushâ€™s administration established a novel initiative to prevent attacks on American interests from the sea, or to prevent transport of fissile materials that could be used in weapons of mass destruction. It was called the Proliferation Security Initiative, or PSI. Two events were uppermost in American minds when it came to security at sea. In 2000, al-Qaeda attacked the USS Cole, an American destroyer, in Yemen, killing 17 U.S. sailors. In 2002, the U.S.