President Trump made a very strong statement today, and it had nothing to do with climate change. Yes, Mr. Trump pulled the United States out of the Paris Agreement on climate change, which will have an effect on climate action worldwide. But he also removed America from an agreement that every country in the world except two has joined. It was one of the most dramatic examples yet of his approach to “America first.”

America has long seen itself as singular, opting out of widely backed global efforts such as an anti-land mine treaty and participation in the International Criminal Court. America’s status as the world’s lone superpower creates unique demands, the thinking goes. But as the world becomes more interconnected, there is increasing momentum to find common purpose in countless ways, from trade to space science.

In opting out of an accord that literally united the globe, Trump made it clear that he is determined to deliver on what his voters wanted: a willingness to buck the rest of the world, even if that means walking alone.