He can walk away and let these two moronic Nations continue to kill each other while we make Popcorn.
That appears to be objective of the meeting with Putin - finding off ramp to our involvement with this war.
Trump has consistently tried everything that neocons like Lindsey Graham and Keith Kellogg have presented to him in regard to leverage and everything they have suggested has failed miserably. They have no credibility left.
It's past time he told them he's done all he can.