This issue is a variant of Comic Cavalcade "Tomorrow the World" (DC, 1945 series) [Original].
Distinguished from the original version by a title and credits panel replacing the original splash panel and a "B" in the contest coupon on the last page.
Adapted from the 1944 movie "Tomorrow, the World!", which was in turn adapted from the 1943 play of the same name.
The play was written by James Gow and Armand d'Usseau. The movie was written by Ring Lardner, Jr. and Leopold Atlas, Interestingly, Gow and d'Usseau are credited in the comic, but Lardner and Atlas (and whoever actually wrote the comic) are not.
The title comes from Adolph Hitler's quote "Today Germany; tomorrow the world."