The day before Mexico's President assured Congress that "dialogue and a negotiated solution are possible" in Central America, two of the region's nations announced that they had arrived at exactly that kind of arrangement. After a daylong meeting in Panama City, Costa Rica and Nicaragua signed an agreement allowing multinational inspection teams along their 192-mile border. The accord was a concrete step toward ending tension that began when Nicaragua attacked U.S.-backed contra guerrillas who operate from Costa Rica.
The Panama City agreement was signed at a meeting of the Contadora group, composed of...