Putting large warships on diesel multiplies the number of useful surface assets, but it also makes diesel a single critical dependency. Germany would have to invest in synthetic plants and other production capacity well before war to support the larger demand. Agricultural fuel could ease the shortage, yet crops devoted to fuel compete directly with food and imported supply remains exposed. Enemy reaction and resource competition therefore limit any apparent German advantage.
Chapter · 1:06:41-1:09:46
A diesel fleet concentrates a strategic vulnerability
Fuel commonality strengthens operations but gives an opponent a clear way to cripple the entire fleet by attacking diesel production and supply.