I searched Mario Schulz’s post at War on the Rocks for an answer to that question in his post “Germans Should Accept What a Military Is For, or Get Used to Disappointment”. I was the one who was disappointed.
Clausewitz answered that question for us: war is the pursuit of policy by other means. The Germans are accomplishing their policy objectives without war and effectively without a military. Why should they bear the costs in blood and money (to coin a cliche) of a military? They’ll always have the United States to bear those costs for them.
The Germans are utterly brilliant. They’ve got France, Italy, Spain and Greece running permanent austerity to accommodate a German current account surplus. Think of the evil genius needed to get whole countries to cut their own throats and think it’s for their own good.