You realize that Russia is a mere 1.400 km from the German border? And I’m not even counting Kaliningrad here.
Bernd Ulrich from Die Zeit summarized it nicely: “Americans are always 4.000 miles bolder when it’s about Russians.”
About the big stick: There is only one reasonable big stick against Russia, if they chose to invade Central and Western Europe: Nuclear Weapons. That’s why American doctrine in those scenarios was “Let’s bomb Germany and annihilate those Russians troops.”
I guess we could fulfill the 2% easily if we’d develop us some nuclear weapons. It’s not like Germany doesn’t know how to mine uranium or to build nuclear reactors, rockets and stealth submarines which can be used to carry ballistic missiles.