The big picture: A spate of arrests has broken out, with detentions of Americans and Canadians in China, Iran and Russia, and Chinese people jailed in Canada and now Poland. It appears to be unprecedented — political hostage-taking amid a modern trade war.

As we’ve reported, the tit-for-tat jailings in part suggest a new stage of hostility in the U.S.-China race for technological and economic dominance in the coming decades.

“The Chinese have set a very troubling precedent. You don’t like it when one of your citizens gets arrested, you nab a few folks from that country,” said Ian Bremmer, president of the Eurasia Group.