Yes Trump is stirring the pot a bit maybe to play Russia against China. Maybe it's to get Europe to spend a little more on NATO so the US doesn't fund the vast majority of that alliance and he can cut some spending there. Whatever the mind set is, not much has changed.
The US and all of its allies are still allies.
Does anyone really think that if some "real" US interests are messed with that the United States won't fuck somebody up? I mean it's just a few years ago we went to war, why all of a sudden are we weak?
Edit: just to clarify "real" interests e.g. a NATO ally is hit, Israel is hit, Japan is hit, South Korea is hit... any US base or military vehicles, etc...