From the Heritage Foundation, I'm Michelle Cordero, and this is Heritage Explains.

Last week, President Donald Trump's national security advisor, John Bolton, resigned from his position.

And the story made headlines across the world.

The headline tonight, yet another staff shake up in the Trump White House.

National Security Advisor John Bolton is out. On his final morning as Donald Trump's National Security Advisor, John Bolton, stepped outside

the West Wing.

It would seem for some privacy.

Inside, a president with whom Bolton was now irreparably

incompatible. John Bolton's priorities and policies just don't line up with the presidents, so the

president made a change. The United States is facing foreign policy challenges on multiple fronts,

from places like Iran, North Korea, Russia, and China.

And with John Bolton now leaving the White House, there are huge questions about how we will

confront all of these challenges.

Bolton was Trump's third national security advisor in less than three years.

That means tonight put a different way.

They are searching for their fourth national security advisor in three years' time.

Well, as we record this podcast today, President Trump has just announced that he will nominate

U.S. hostage negotiator Robert O'Brien to replace John Bolton. So how important is this role?

With all of the recent media coverage, it seems pretty high profile, right? Yet it's not a

cabinet role. Today's guest, James Carafano, explains the history and evolution of the role of national security advisor.

For example, did you know that Reagan had six national security advisors?

We discuss what the nature of the job actually is, and if there's any real effect on policy.

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