(CNN) Former US ambassador to NATO and current president of the Chicago Council on Global Affairs, Ivo Daalder, says the United States is "no longer the most important actor" on the world stage.

"In 2017...the United States was a major, major presence in the mind of global leaders. It mattered what the US thought, did, or didn't do. I'm not clear that in 2021, the world's leaders will still be thinking about what the United States is going to do," Daalder told David Axelrod on The Axe Files, a podcast from CNN and The University of Chicago Institute of Politics.

Here are three tenets Daadler stressed regarding the United States' role in foreign affairs:

1. What happens beyond the US will "have an impact" on what happens inside [US] borders.

In the 1990s, "you had a series of crises—Somalia, Haiti, Bosnia—that brought to the forefront this idea that, maybe you couldn't ignore what was happening in the world. And you really had to start thinking about how to deal with the world in a way that made sure that American leadership...was necessary."

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