Delta Force
Banned
What if the Germans had decided not to build the Atlantic Wall? How else could they have defended their coastline, and what else might the resources and personnel allocated to it have been used for?
Depends on if they go with Rundstedt's plan of a reserve or Rommel's penny pack the devisions behind the coast plan or go with Hitler's idea he made OTL of splitting the baby in half and taking divisional command for himself.
How much infrastructure could Germany harden if it used the steel and concrete for that instead of fortifying the entire Atlantic coastline?
Twice on Italy the Germans tried variations of the outpost/interior battle approach. That is a light guard on the coast and a large counter attack force in reserve in the interior. It did not work either. @ Salerno a powerfull armored corps attacked within 48 hours and was shot to pieces in its repeated attacks. At Anzio a entire army was massed against the landing force as it attempted too move into the interior. That failed too. On Sicilly the coast was fortified (not as well as Normandy or Pas de Calais) & a armored corps attempted to destroy just one isolated beach head, that failed.
In the Pacific the Japanese tried a variety of variations on these and failed. On Luzon & Leyte the had a light beach defense along the coast and placed a large army in the interior to destroy the enemy inland. That failed, and it failed again on Okinawa.
The problem in every case was the Allies came to the battle with more firepower than the defense could cope with. & in several cases better manuverability.
The simple answer is quite a lot. Also factor in the labor utilized to build the wall. This could have made difference concerning the existing plans to not only harden but expand (and therefore disperse) their "synthetic" fuel production by building new plants. There were plans that were not executed OTL due to lack of materials and labor. Some expansion was done to existing facilities, but construction of new facilities faltered due to lack of materials and labor. In reality it would not have been that difficult to "harden" a hydrogenation plant due to the fact that Allied bombing inaccuracy limited the amount of "critical" damage done during a raid (most damage was to surface piping and the "critical" parts were too small to hit other than by small statistical chance).
Quite correct. All the more reason not to waste time, materials, money and labor on the wall. Don't immediately recall the source, but "defend everywhere, defend nowhere" certainly applied. It was an expensive, wasteful thin crust.
Does this change the outcome of the war? No. Does it shorten the time to a cross channel attack? Not by much.