Victor Davis Hanson uses a National Review Online column to describe what he labels the “method to Trump’s madness.”

Critics of Donald Trump claim that there’s no rhyme or reason to his foreign policy. But if there is a consistency, it might be called reciprocity.

Trump tries to force other countries to treat the U.S. as the U.S. treats them. In “don’t tread on me” style, he also warns enemies that any aggressive act will be replied to in kind.

The underlying principle of Trump commercial reciprocity is that the United States is no longer powerful or wealthy enough to alone underwrite the security of the West. It can no longer assume sole enforcement of the rules and protocols of the post-war global order.

This year there have been none of the usual Iranian provocations — frequent during the Obama administration — of harassing American ships in the Persian Gulf. Apparently, the Iranians now realize that anything they do to an American ship will be replied to with overwhelming force.

Ditto North Korea. After lots of threats from Kim Jong-un about using his new ballistic missiles against the United States, Trump warned that he would use America’s far greater arsenal to eliminate North Korea’s arsenal for good.

Trump is said to be undermining NATO by questioning its usefulness some 69 years after its founding. Yet this is not 1948, and Germany is no longer down. The United States is always in. And Russia is hardly out but is instead cutting energy deals with the Europeans.