Congress has approved legislation that would prevent any president from withdrawing the United States from NATO without approval from the Senate or an Act of Congress. The measure, spearheaded by Sens. Tim Kaine (D-Va.) and Marco Rubio (R-Fla.), was included in the annual National Defense Authorization Act, which passed out of the House on Thursday and is expected to be signed by President Biden.
I don’t think it suggests they believe he will return, but that it’s a serious enough possibility they should do something to prevent a seriously bad outcome. With a 25% chance of a Trump win, this kind of prevention is worth doing… and it’s unfortunately probably above that.