Josh Keating covers international affairs for Slate.

So when there's something I don't quite get in the world of foreign policy, he's the guy I get on the phone.

This week, I needed him.

I'm hoping you can explain this tweet today from Mike Pompeo.

You ready?

Yeah. Oh, let me just get that exactly what he said on the tweet.

This tweet is by far the most talked about thing that Mike Pompeo has done online in the last

couple of days. But it's written in a kind of code.

It says, today I reported to Congress that Hong Kong is no longer

autonomous from China, given facts on the ground. Then Pompeo says, the United States stands with the

people of Hong Kong. Yeah, so this overturns a policy dating back to 1992.

Josh says to understand what Pompeo is driving at here, you need to know that since the early

90s, Hong Kong has had this special status with the U.S.

The U.S. actually considers Hong Kong a separate political entity from the rest of China.

So what does that mean?

Yeah, so this is important.

This means things like the tariffs that the U.S. placed on Chinese exports during the recent trade war don't apply to Hong Kong.

It means that there are different visa rules for travelers from Hong Kong.

And China likes this. It helps them attract businesses that want to dip their toes into the region.

And likewise, when Chinese companies want to expand internationally, they often start by sort of listing themselves on the Hong Kong stock market.

So Mike Pompeo pulling the special status, what does that mean?

Yeah, so a bill that was passed last year during the Hong Kong protests by Congress basically requires the Secretary of State to certify every year that Hong Kong is still sufficiently autonomous to be granted this special status.

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