My understanding is that he can launch any military attack he wants, just that he has to come up with a pretext that conforms to the War Powers act.Pretty much nailed on that he would want to at least one of those judging by what I read.
But can he actually just do that? Like just on his say so?
"It provides that the U.S. President can send U.S. Armed Forces into action abroad only by declaration of war by Congress, "statutory authorization," or in case of "a national emergency created by attack upon the United States, its territories or possessions, or its armed forces.
The War Powers Resolution requires the President to notify Congress within 48 hours of committing armed forces to military action and forbids armed forces from remaining for more than 60 days, with a further 30-day withdrawal period, without a Congressional authorization for use of military force (AUMF) or a declaration of war by the United States. The resolution was passed by two-thirds of Congress, overriding the veto of the bill from President Nixon."
I don't think he has as much autonomy with trade but, like the admin is currently trying to do with healthcare, I believe there are ways they can undermine agreements through department action/inaction and executive orders on specific items like tariffs.