(CNN) Donald Trump ran on a simple slogan: He would Make America Great Again. But what's clear from his reaction to threats from Iran in the wake of the killing of Qasem Soleimani is that he doesn't really get what made America great in the first place.

In the wake of the American drone strike that killed Soleimani, Trump tweeted that if Iran retaliated, they should know that he (and the United States) had already "targeted 52 Iranian sites (representing the 52 American hostages taken by Iran many years ago), some at a very high level & important to Iran & the Iranian culture."

Secretary of State Mike Pompeo sought to walk back that threat -- of hitting cultural sites, which the International Criminal Court has judged to be a war crime -- in a series of interviews on Sunday. But Trump was adamant on the way back to the White House Sunday evening that he would do exactly what he said he would do.

"They're allowed to kill our people, they're allowed to torture and maim our people, they're allowed to use roadside bombs and blow up our people, and we're not allowed to touch their cultural sites?" Trump told reporters. "It doesn't work that way."

Don't dismiss this as just more bluster from the President of the United States. It is bluster, but it's also revealing about how little he understands the idea of American exceptionalism that he ostensibly ran and won on in 2016.

Read More