There is a huge issue with that unfortunately.
Our armed forces and theirs are so inrtinsically linked right now, there really can't be such a "break". It's not just about the leaders.
From a training point of view we are regularly training together, both over there, and in the UK (Europe), this can't be simply ended overnight by us, even trump would struggle to do it, and he'll be firmly advised by their military leaders (no mater who he sacks/promotes) that it can't be done, it will take years.
It's not just us either, Germany, France, Italy, Spain, are all in the same position, their whole armed forces are similiraly linked (embedded) within the US armed forces, in training, operations, and equipment.