HUNGRY and exhausted Armenian families jammed roads to flee homes in the defeated breakaway enclave of Nagorno-Karabakh, while the United States called on Azerbaijan to protect civilians and let in aid. The Armenians of Karabakh - part of Azerbaijan beyond Baku's control since the dissolution of the Soviet Union - began fleeing this week after their forces were routed in a lightning military operation by Azerbaijan's military. At least 13,550 of the 120,000 ethnic Armenians who call Nagorno-Karabakh home arrived in Armenia on the first day of the exodus, with hundreds of cars and buses crammed with belongings snaking down the mountain…