The Ozone layer, which mostly lies on the lower portion of the stratosphere.
How Long Did The Vietnam War Last. The Vietnam War is the longest war ever to have taken place in the American history. It lasted for 16 years and it was terrible for the Americans at that time as the Civil Rights campaign was at its peak and so also the Vietnam War and anti war protests.
As for the Vietnamese, they experienced the First Indochina War (also known as the Indochina War or Anti-French War) against the French from December 19, 1946 until August 1, 1954 right before the Vietnam War (Second Indochina War). So for them it was nearly 30 years altogether. It is worth noticing that Vietnam invaded Cambodia in the wake of the Vietnam War to overthrow the genocidal Khmer Rouge regime in the war which would last until September 1989.