It's Donald Trump's war now. The decision to bomb Iran illustrates the conflict between some of the president's fundamental impulses.

Even as he announced the strikes on Iran, President Trump appeared to be rapidly trying to get himself back to the middle by insisting the operation was a one-off.

Trump has long been critical of U.S. military intervention overseas, but he has now become the first U.S. president to bomb Iran. Presidential Historian Douglas Brinkley joins “The Weekend: Primetime” to discuss how it could affect his legacy.