This idea that the president has unrestricted ability to set foreign policy is an invention of this particular administration. In truth, powers are split between the executive and legislative branches [1].
Most notably, only Congress can declare war, which has been a real sticking point in the last century and why, for example, the Korean War wasn't technically a war (it was a "police action") and why the Vietnam War wasn't either. The First and Second Gulf Wars and the War in Afghanistan at least had explicit war resolutions passed by Congress, however misguided.
Brown pelicans typically lay three eggs. Some bird species can employ "deferred incubation" such that even when eggs are born on separate days, the eggs will hatch at the same time. Brown pelicans don't do this so the chicks hatch 2-3 days apart each. The eldest gets fed more so there ends up being a size difference. What inevitably happens is the eldest two conspire to push the youngest out of the nest. If it falls out, the parents won't feed it and it will die. Then after awhile the oldest pushes and second out. 90%+ of the time only the eldest ever fledges.
Why did I tell this story? Because it basically mirros what's going on with our government. We have, at least theoretically, three branches of government that are meant to balance each other. There has been a conservative takeover of the executive and judicial branches such as to neuter the legislative branch. This Supreme Court has both stripped Congress of power (eg overturning Chevron) and empowered the presidency (eg the presidential immunity decision that had absolutely zero basis in anything; it was simply invented). They've invented doctrines to allow them to overturn basically anything Congress does (eg "major questions" and "historical tradition"). This is a coup d'etat and the end result of the 50+ year Republican Project.
What happens next, just like the pelicans, is the courts gets neutered. Conservatives now push the "unitary executive" philosophy, which is a fancy way of saying they want a dictator, not beholden to any courts or lawmkaing body. The second chick is getting pushed out of the nest. The administration is openly defying the courts on many matters (eg Kilmer Abrego Garcia) and this Supreme Court has given them the immunity to do that.
I, personally, think we are beyond the point of no return. Electoral politics cannot possibly fix this situation. At the same time, the American empire is decline. We are going to see firsthand waht a dying empire looks like and I guarantee you it won't be pretty.
[1]: https://www.cfr.org/backgrounder/us-foreign-policy-powers-co...