Large-scale American support began during the Kennedy Administration in the early 1960s, with the arrival of large numbers of the US Special Forces to help out in the field. The arrival of helicopters changed the nature of the battle considerably. Helicopters enabled South Vietnamese soldiers to quickly fly to almost any point in the country, leaving little time for a retreat. Throughout 1962, the combined forces were increasingly effective in routing the VC. These tactics, combined with the use of armored personnel carriers, took a heavy toll on various fledgling VC units. The lightly armed VC had no weaponry capable of stopping the armored carriers and inevitably were forced to flee, taking heavy casualties.