SEOUL, South Korea – North Korea fired four missiles off its eastern coast Saturday, South Korea said, in what was likely to be seen as a message of defiance to the United States on its Independence Day holiday. The launches, which came two days after North Korea fired four short-range missiles, could further escalate tensions in the region as the U.S. tries to muster support for tough enforcement of the U.N. resolution imposed on the communist regime for its May nuclear test. South Korea's Joint Chiefs of Staff said three missiles were fired early Saturday and the fourth at about...