After the 1944 D-Day landings, Allied planners thought that the war might easily stretch into 1946. The original plan was to drop dozens of atomic bombs on Germany. There was no such thing as "Let's sign a peace treaty where we stop fighting the Germans without invading Germany." You seem to be proposing that when we got to the German border in March 1945 we should have suddenly decided not to enter German territory, but only blockade them instead. The only reason we didn't drop dozens of bombs on both Germany and Japan was that our production lines didn't reach their three bombs per month full capacity until June.