It's not the cost itself. 40 PERCENT of GDP went toward war production in the 1940s. Almost half of everything we produced was to win the war. The other 60 percent largely went to feeding and clothing and housing the people working on the war effort, and keeping the lights on, etc. since they were no longer producing those things.

Everyone in the whole society was literally working on the same thing toward the same goal at the same time. There's simply no comparison with that to anything we've experienced since then. That kind of thing can't be measured in dollars.