Since World War II the United States military has been one of the largest forces in the world. Tasked with maintaining global peace, a sizable force has been needed to maintain their many global bases. This chart shows the total United States armed forces post World War II by year.
Prior to World War II a large peacetime standing army wasn’t normal. Given the high costs to maintain a large military, the US would drastically reduce the number of personnel after wars or conflicts ended. Despite a huge ramp up in military size for World War I, afterwards the army size was reduced to pre-war levels.
United States Armed Forces Post World War II
To meet the demands of a multi-front, global war in World War II, the military grew to its largest size ever. There were nearly 12 million active duty military personnel during the war, dwarfing any size since then.
Following World War II, the US maintained a significant military size due to the demands of the Cold War. Even more troops were needed for the active conflicts such as the Korean and Vietnamese wars. Following the Korean War that ended in 1953, the military did see a decrease in personnel. This only lasted a decade or so due to the escalating conflict in Vietnam during the 1960s. This war required the most active duty troops (over 3 million) than at any time since WWII.
Since the Vietnam War, the US military has gone through many changes and restructuring. The draft was ended and the military moved to an all volunteer force, though conscription is still an option if ever needed via the Selective Service System. During the Cold War the US military size never dropped below 2 million personnel.
When the Cold War and First Iraq War (ie – Desert Storm) ended in the early 90s, the military faced a large reduction in size. The armed forces personnel dropped between 25-30%, with some branches affected more than others. Since then, the US has maintained a relatively steady number of troops despite the Middle East conflicts of the early 21st century.
Source: History in Pieces