Peacetime forces supplied the core for wartime expansion

The comparison uses a long British peacetime defence-spending baseline of roughly 3 percent of national output, with much larger peaks during major wars. The interwar figures quoted here are about 2.6 to 2.7 percent, and the definition of defence spending changes over time. The funding argument is that standing forces must handle routine demands and the initial problems of war while retaining the organization needed to expand. Alliances supply one kind of insurance, while standing forces are compared with emergency services that must already exist when needed. In this interpretation, the jump to about 38 percent of national output in 1941 depended on the military core maintained before the war. The comparison then reaches a wartime peak near 53 percent and substantial reductions after 1945.