By March 1979, the Somoza regime faced an open civil war as well as being cut off from all aid by the United States, including blocking of an emergency shipment of weapons and ammunition coming from Israel. With ammunition, spare parts, fuel, and medical supplies running dangerously low, the increasingly hard-pressed National Guard could no longer sustain a prolonged fight against the rebels. Already plagued by shaky morale, and weakened by casualties and desertions after seven weeks of battle, GN units were gradually forced to fall back to Managua.