I think that with the price of oil so low, it doesn't really matter. Germany should be footing the bills in any case. Germany and eastern Europe have every ability to get their shit together.
I know some people want to predict a doomsday if Putin recaptures more ex-Soviet territory, but that's just hogwash. While I feel bad for some of those people, there comes a point where we just cannot afford to play policeman for the world. We are on the way to becoming very Russia-like ourselves, unless we start exercising some sense, and focusing our energy and efforts on the homefront.
Looking past the next five years, if we want to be in a position to play world police fifteen years from now, we have many internal issues to address. On our current path, it isn't terribly long, in a historical sense anyhow, before our national energy is exhausted. Instead of a creeping withdrawal from acting as a hyperpower incrementally today, we might see a sudden catastrophic collapse in the future. As it stands, even when we don't overtly act, other polities still know we are here watching.
Should our eventual collapse create a true vacuum of power in the future, see how we do stumble into a doomsday scenario.