There's talk that China may have quietly floated a deal with Washington — abandon Iran in exchange for a free hand on Taiwan — which would be bad news for both Tehran and Taipei.

• The rumored offer: China stops buying Iranian oil and even backs regime change there, if the U.S. looks away from Taiwan.
• Iran would lose its biggest oil customer and its main diplomatic shield in one move.
• Taiwan is the catch — trading it away would hand China the world's most important chip industry.
• The odds of some version of this message already reaching Trump's team are put at about 75%.

Outlook: No deal is confirmed, but expect more signals that China is testing how much the U.S. will trade for cooperation on Iran.