Bush presided over the invasion of Panama and the Gulf War, ending the Iraqi occupation of Kuwait in the latter conflict. Though the agreement was not ratified until after he left office, Bush negotiated and signed the North American Free Trade Agreement (NAFTA), which created a trade bloc consisting of the United States, Canada, and Mexico. Domestically, Bush reneged on a 1988 campaign promise by signing a bill that increased taxes and helped reduce the federal budget deficit. Following the end of World War II, Bush enrolled at Yale University, where he took part in an accelerated program that enabled him to graduate in two and a half years rather than the usual four. He was a member of the Delta Kappa Epsilon fraternity and was elected its president. He also captained the Yale baseball team and played in the first two College World Series as a left-handed first baseman. Like his father, he was a member of the Yale cheerleading squad and was initiated into the Skull and Bones secret society.