I think Trump will do the exact same thing as Obama did (I.E. mostly stand by on the sidelines and support the soldiers from other countries - notably Iraq - actually doing the fighting), then take credit for ISIS's inevitable defeat.
That's the joke of it - even before Trump's election, ISIS was well on its way to defeat. They were never a credible threat to America or global stability; no more so, at any rate, than every other whackjob terrorist organization that has reared its head in the last few decades.
Kill 1 man: You are a murderer. Kill 10 men: You are a monster.
Kill 100 men: You are a hero. Kill 10,000 men, you are a conqueror!