If one wanted to take the Maximalist view of "America First" and assign only the worst motives to what Trump is saying, then sure. But a realistic reading of the world situation would cause any serious student of foreign policy to reject such a posture.

It's not a maximalist view.

For "America First" to have any meaning, it has to signify something more than just acknowledging that America has interest and those should be taken into consideration in our foreign policy. Because no one has every disagreed with that, ever.

Presumably it reflects a change in our foreign and economic policy - reprioritizing the importance of America's direct interests relative to those interests we pursue by taking into account the interests of our allies. Of course that doesn't mean that we're going to start treating a nation like Canada as an enemy, but it means we're going to start treating them more as a rival for economic and foreign policy position than we have historically. Denmark as well.

But it's irrational to think that we can pursue that type of foreign and economic policy and not expect other countries to respond in kind. That somehow we can de-emphasize their interests in our calculus without having them de-emphasize our interests in theirs.

Of course it's a spectrum, not a binary. But if we're shifting the way we treat other countries along that "Allies-Rivals-Adversaries" spectrum so that we can put "America First," we have to expect that they'll respond in kind.