In 1918 during WWI, US GDP was $75.8 billion and the budget deficit was 12% of GDP. In 1919, GDP was $78.3 billion; the deficit, 17% of GDP. By 1942, GDP was $148 billion and the wartime deficit was 14% of GDP. By 1943, GDP was $185 billion while the deficit peaked at a staggering 30% of GDP, twice total government revenues. War is costly, the alternative is more costly.