What major difficulties did the US Army face in Vietnam?

Answer 1

There were a number of elements that made fighting in Vietnam difficult for Americans. Among these were the language/culture differences, thick jungles and mountainous terrain, swamp and bogs, monsoons and swollen rivers, lack of acclimatization of occupying forces (French then US troops), difficulty identifying the enemy (a guerrilla force that blended with the homogenous population), lack of home front support (growing social unrest and antiwar sentiment), unclear objectives, ineffective (puppet) government in South Vietnam, unsteady (rotating seat of power) ally government, long supply lines (approximately 8,000 miles of ocean between the US and Vietnam), and a host of other reasons.

Answer 2

By 1969, the VC was practically a "harassment" force. They had been pretty well destroyed during the tet offensive of '68. They still existed of course, but were no where near the power they once were. The main adversary after '68 were the NVA...a determined and well desciplined force. Battling the NVA "grunt to grunt" was a fight to the death.

Answer 3

Living conditions (no air conditioning, no clear clean cold drinking water, no television, no women, etc.); the weather; the enemy; their fellow Americans.