"It's a common courtesy when a military official from another government salutes, that you return"

This is, I believe, very much correct.

Yes he did, but I’ma let it slide because it was hilarious.

To expand on what BobLibDem said: I agree completely that if Obama, as President, had done exactly what Trump did – returned the salute of a North Korean general at an NK diplomatic summit – the Republican punditry would have offered up even more pointed criticism than we’re seeing now directed at Trump.

Because this is genuinely a non-issue, the criticism arises not from ire at the act, but a desire to score points against the actor. There were eight years of such criticisms directed against President Obama.

I think so as well. If Republicans hadn’t spent the last eight years demonizing Obama for every shortcoming, real or imagined, we wouldn’t see the hubbub over Donald’s salute. I don’t see Democrats milking this like Republicans couldn’t let go of the tan suit or the “apology tour”, the fuss will quickly fade and indeed I don’t think Democrats have really made that big a deal about it.

I dunno. As a former Navy man and a bit of a prescriptivist wrt proper saluting protocol, I’m still kinda annoyed about Reagan having returned salutes. Also about the embrace of the habit by subsequent POTUSes (POTI? :wink: ). However, I do like to tell myself that Clinton and Obama would have happily eschewed the practice were it not for the likelihood of disingenuous pearl-clutching excoriations from disingenuous right-wing reactionary pearl-clutchers.