On a snowy tarmac at Amari Air Base in northern Estonia on Sunday morning, pallets of rifles, ammunition and other weapons were being loaded onto one of the largest cargo planes in the world, an Antonov AN-124, belonging to the Ukrainian air force. It is an artifact of the Cold War, built and purchased when Ukraine was still part of the Soviet Union. ... In less than a week, the United States and NATO have pushed more than 17,000 antitank weapons, including Javelin missiles, over the borders of Poland and Romania, unloading them from giant military cargo planes so they...