Trump is presenting a theoretical construct of foreign policy that is even simpler than Reagan's was, which, ironically, is the last time the US actually had a coherent foreign policy.
This world view is: If you are "bad," you are Trump's "enemy."
If you are muslim, you are bad. Therefore, if you are muslim, you are Trump's enemy.
If you don't do what Trump wants, you are bad. Therefore, if you don't pay for Trump's wall, then you, Mexico, are Trump's enemy.
If you send Trump refugees, you are bad. Therefore, you, Australia, are Trump's enemy.
If you aren't bad, you aren't Trump's enemy. Putin, according to Trump, is not bad, and therefore isn't an enemy.
What has yet to be defined are the words "bad" and "enemy." What does it mean to be bad? Are there degrees of enemy?
We do know that"bad" is something that can be subjected to a multiplier effect.
North Korea is developing a nuclear weapon, (bad) China is expanding into the South China Sea (bad), international trade deals are bad, and, of course, the media is bad. However, because ISIS incorporates two bads (terror and Islam) it is a double bad, followed closely by Iran (Islam and a "bad deal") which is a bad and a half. Thus, Trump's focus on ISIS and Iran, despite neither posing an existential threat to the United States security at the moment.
Putin is personally admirable for Trump (for reasons that defy explanation at the moment) and is against ISIS. Therefore, Russia can not be bad and can not be an enemy.
Trump is approaching the conduct of international diplomacy from the standpoint of a real estate deal. To sell property, you pump the tires, you hyperbolize and accentuate the positives while denying knowledge of the negatives. (If I don't see the house inspection, I don't know that the foundation is crumbling, do I?) As a result, everything is really big and seemingly equally important. Trump also has shown that he believes that any publicity is good publicity, so he is not hesitating to put everything out there, good, bad or indifferent.
Diplomacy is traditionally a language of subtlety and nuance, and is best done out of the public eye. Trump is neither of those, and is a publicity whore.
I'm no expert, but I don't see this going all that well...