Donald Trump’s mantra that he would “make America great again” has hit another snag.

That’s my view at least.

You see, a great nation’s president doesn’t diss its allies. It doesn’t do the dirty work of disrupting a key international alliance on behalf of our nation’s top adversary. The president doesn’t conflate trade issues with defense alliances.

The president doesn’t open his mouth without knowing what the hell he is talking about.

Donald Trump is making a hash out of our alliance with the North Atlantic Treaty Organization. He makes a valid point about NATO nations needing to pony up more cash to pay for their own defense.

It’s his style. It’s his clumsy rhetoric. It’s his ignorance of NATO’s very founding that drives many of us nuts.

A president who wants to make America great again doesn’t get disinvited to London by that city’s mayor because of the disgraceful comments he has made about Muslims; oh, yes, the London mayor — Sadiq Khan — happens to worship the Islamic faith.

After the president finishes trashing NATO and uttering preposterous statements, the president is heading to Helsinki, Finland, to meet with Russian strongman Vladimir Putin. The two men are going to meet in a room with no senior aides present; they’ll have their interpreters, that’s it!

What in the world is Trump going to give to Putin? What is he going to tell him? What is he going to demand of him?

And what are we supposed to believe from the Liar in Chief when he comes out of that meeting and delivers his version of what happened behind closed doors?

This isn’t how you make America great again.