I wouldn’t call the US a nation of cowards, but Bryan Caplan would — after calculating how few young men volunteered after Pearl Harbor:
According to the 1940 Census (table No. 11), the U.S. had 6.2 million males ages 15-19, 5.7 million males ages 20-24, and and 5.5 million ages 25-29. That’s 17.4 million men of combat age. Let’s use David’s high figure of 140k [volunteers] for all three months. This means that during the first three months of U.S. involvement — a period where our national mythology describes a whole generation rushing to volunteer — just 2.4% actually did.