Whatever he does will affect World Politics and Peace.
Most certainly for the positive. No, not in general, but moreso than the other candidates.
Why? Because Hillary is a warmongering neoconservative through and through. Billy Kristol would rather have her than Trump.
This is the only thing any of the candidates differ in any significant capacity IMO.
All (hyperbole ahoy!) of them are watered down Bernie on economic issues, all of which will cause ruin to one degree or another.
Trump, however, is the only one to state anything like "I could get along with Putin." Meanwhile Killary has said "Putin is a threat to peace." The fact she forwards the propaganda about the whole Ukrainian debacle, the politicians of Kiev being controlled by western intelligence and the foe of the Ukrainian people, and all the rest, is telling. You don't want WW3, then have Russia and the US on good terms.
Trump said he wanted to end NATO (NATO's enemy doesn't exist any more, and treaties are a danger to peace, as WW1 showed us, and as Turkey is attempting to show us now); that US soldiers should leave Korea, German, Japan, etc. (Another good! It will be a blow to the military industrial congressional complex, not to mention the people living near our military bases will feel safer (because the US insists on trying their soliders in military court instead of local courts, the former of which are notoriously lenient, so we have a perverse incentive on our boys to do evil like the all time classic ****) AND maybe the nations will pick up their own military production so they can defend themselves and deal with issues, like Japan with China in the South China Sea (which was instigated by American maneuvers, mind, just like Japan with Pearl Harbor as we blockaded their oil routes and were aiding their foes in Europe, known to be coming by Eisenhower (who wanted an excuse to go to war, so he let their navy come along), so not all interest is beholden to an empire.) He said of dictators Saddam Hussain and Muammar Ghadafi, sure, they were monsters, but at least they fought the far-worse ISIL type terrorists! He said we were mistaken to get into the Middle East. He asked are Iraq and Libya better off for our intervention? He answered with a resounding No. And now they want to go into Syria? Not on my watch, he averred.
Sorry for messy post. Copy pasted and edited bits.
Edit: I should mention two. Bernie supported the Kosovo wars, Afghanistan and Iraq, etc. He's not anti-war in voting. Gary Johnson isn't principled, but he vaguely opposes interventionism.