I'd be shocked if Trump actually ended the war rather than begrudgingly doubling down out of fear of looking "weak". He's nothing if not petty and ego driven. In the unlikely event he does actually fracture NATO or allow a negotiated end to the war, there's a credible argument that would make him probably the best president in my lifetime. I think "personally preventing WW3" tops any other recent presidential achievements like creating a federal department of ethnic cleansing and illegal domestic surveillance infrastructure (Bush/Biden), destroying Iraq (Bush/Biden), destroying Afghanistan (Bush/Biden), destroying Libya (Obama/Biden), or pulling a bait and switch to implement RomneyCare (Obama/Biden).