President Barack Obama made a previously unannounced visit to Afghanistan on Tuesday, the first anniversary of the U.S. raid that killed Osama bin Laden in neighboring Pakistan. The president will make a televised address from Afghanistan at 7:30 p.m. ET. The trip was Obama's third to Afghanistan since taking office. He visited in March 2010 and returned in December of the same year. He also visited Afghanistan in 2008 as a presidential candidate. Tuesday's visit came at a particularly delicate time in relations between the United States and Afghanistan. The countries have been negotiating a strategic agreement that would outline...