As we (U.S.) hadn’t entered the war by that time, am I right to think Germany focused most if not all of its attention on the Eastern Front?
You’re correct. The US wasn’t in the war, Britain did not have the capability to invade France, Spain was friendly to the Nazis. Europe was, at that point, basically secure for Hitler. The only land fronts the Reich had active in summer 1941, after they smashed Greece and Yugoslavia, were the USSR and North Africa.
The Ostfront was always the “big” war front to the Germans up to the very end.
}:-)4