I suspect that this has more to do with Ukraine than it does the USA. Russia seemed like one of those plastic owls to fend off birds then suddenly turned its head and ate one.
I don’t think Trump is particularly crazy like a fox, but Europe taking its defense into its own hands in a coherent, credible manner has been the goal of US European policy across at least the last six or seven administrations of both parties.
https://youtu.be/NFw7ZifqhTg?si=IujBLjIsaQysNHmp&t=267
4:27
“The time when we conveniently let the United States carry the burden for our security is over. The US is absolutely committed to NATO, but this commitment comes with a clear and long standing expectation, that Europe and Canada take more responsibly for their own security, and I believe that is only fair.” -Mark Rutte