If the US pulls out of NATO, then it's true that Europe has very little reason to support American interests (unless America "pulls out" of NATO by renegotiating a new mutual defense pact, in which case the countries in that treaty obviously will have plenty of reason to support America — similar to how Trump replaced NAFTA with the USMCA in his first term; which is also what Trump has said he wants to do with NATO).

However, that is an "if" statement that has not come to pass.