It's not a fair comparison, because world population in 1940 was just 2.3 billion. So, in relative terms, WW2 killed almost four times as many people per year a

It's not a fair comparison, because world population in 1940 was just 2.3 billion. So, in relative terms, WW2 killed almost four times as many people per year as cancer does. Not to mention that the goal of WW2 spending wasn't to improve some abstract death prevention statistics, it was actually to prevent madmen from taking over the whole world and turning it into totalitarian hell.