As Hitler saw increasing danger from the western Allies, he relied more on Admiral Karl D[odie]nitz to hold them off by submarine warfare. When that effort was blunted in 1943, he both supported the building of new types of submarines and geared strategy on the northern portion of the Eastern Front to protection of the Baltic area, where new submarines and crews could be run in. Enormous resources were also allocated to new weapons designed to destroy London. It was Hitler’s hope that the Germans could drive any Allied troops who landed in the west into the sea and then move substantial forces east in the interval before any second invasion. When this plan failed, Hitler turned to holding all ports as long as possible, to hamper Allied supply lines and to prepare for a counterstroke that would defeat the western Allies. This counterstroke, the Battle of the Bulge , would then provide the opportunity to move forces east after all.