BRUSSELS — The small Balkan country of Macedonia took a big step Wednesday toward becoming the 30th member of NATO, the world’s biggest military alliance. In a move that marked the end of a long dispute with Greece over Macedonia’s name, and less than two decades after NATO deployed troops to the country as it teetered on the brink of civil war, NATO Secretary-General Jens Stoltenberg and Macedonian Foreign Minister Nikola Dimitrov led an “accession protocol” signing ceremony at the alliance’s Brussels headquarters. “This is a historic occasion,” Stoltenberg told NATO country envoys before they put pen to paper. “We have waited for you to join our family for a long time.