The tactical decisions on what forces are needed should be made by those best suited to make them.
The United States spends 4.4% of its GDP on defense; Germany only 1.3%. Germany is the leading country of Europe. The front line nations of Poland and the Baltic States expend 0.8-2.0% of their respective GDPs on defense. NATO was organized to provide defense against Soviet aggression. Russia under Putin is the nearest parallel to the Soviet threat. The most recent mass terror strikes have been in Europe. The Europeans must spend more on their militaries and not rely as much on Uncle Sam.