Awareness of the possibility of an alliance between Japan and Germany, (along with Italy), predates the war's outbreak in 1939. The first cartoon here is from April-May of 1939. Beck is Jozef Beck, the Polish foreign minister. After unsuccessfully trying to play Germany and Russia off against each other, he formed the alliance with Britain and France that brought them into the war when Poland was invaded by Germany and Russia. With the US's entry into the war, the alliance between Germany and Japan gets increasing attention.