US defense spending has fallen steadily since 1945.
In round numbers, here are the peak spending levels since:
- 1944 World War II peak ~40+% of GDP
- 1952 Korean War peaked at 15% of GDP
- 1968 Vietnam War peaked at 10% of GDP
- 1986 Cold War Reagan peaked at 7% of GDP
- 2008 War on Terror peaked at 5% of GDP
- 2020 Trump military buildup peaked at 4% of GDP
- Today circa 3% of GDP.
This graph goes all the way back to 1792.
Note previous wars, 1812, 1846, 1860s, 1918 and 1940s.