Why did the United States lose so much in the Vietnam War?

Mainly because the US military was caught in a jungle guerrilla war in Vietnam, its tanks, planes and other advanced weapons were useless. Vietnamese who are familiar with the environment can lead American troops into their familiar areas and then launch a surprise attack. The us military cannot prevent natural losses. Coupled with the hot and humid climate in Vietnam, all kinds of poisonous insects and snakes grow, and the US military, which is not used to the climate and does not know how to deal with local poisonous creatures, can only slowly consume them. In the end, the Vietnamese fought for years, with strong folk customs and skillful tactics, which also caused heavy losses to the US military.

Now Iraq is a desert, and the enemy has almost nowhere to hide. It is just suitable for the operational advantages of US tanks and helicopters. The US military can naturally destroy the enemy more easily without going near the jungle that is easy to hide. Surrounded by American allies Saudi Arabia, Israel and Jordan. Logistical support keeps flowing. So it is relatively easy for the US military to win now. However, it does not mean that the losses of the US military are small. So far, the US military has suffered more than 6,000 casualties in two wars, only six years, with an average of more than 1000 per year. If the United States can't withdraw its troops even after so many years in Vietnam, the result will actually be exactly the same, becoming another Vietnam.