Obama had reached a diplomatic agreement with Iran on their nuclear program
But he held the line on Iraq and even opened up fronts in Syria. If the Iranian military left itself exposed like that? Obama might be willing to take the shot, if he thought he could advance his position further in the region.
Trump was a big step backwards there, as he was on Cuba. Even with the DPRK I don't think anything substantive materialized.
Obama was trying to carrot the Cubans toward privatization after decades of stick. But he was just as invested in an eventual corporate takeover as Clinton or Carter.
Trump was a flailing putz who did everything for attention. His moves weren't strategic past the next headline.
Looking at everything reasonable in Trump's favor, he was just as bad as Obama on foreign policy.
He was worse in strategy, which made him better in consequence. He undermined international institutions and tried to grift NATO states. He made catty remarks and empty threats to look tough, without having any kind of interest in a protracted commitment to any one conflict.
A Trump mix up at the White House would force another big wave of resignations and bring in a bunch of new grifters and know nothings.
Whether that would be better or worse is forever up to debate. But it will erode US statecraft faster than a stable continuous second term.