The head of state wants to renegotiate a major free-trade agreement, and there is a deal on the table that has been agreed to by all parties. Now all that's needed is for domestic lawmakers to approve the deal. There are signs they might not be willing to do so. In order to concentrate the legislators' minds, the leader exits the old agreement, leaving a stark choice: Either accept the new one, or embrace the chaos of a no-deal exit.
The big picture: Theresa May pulled this move when she triggered Article 50 in March 2017, raising the specter of a catastrophic no-deal Brexit should Parliament not agree to a deal by March 29, 2019. Now, Donald Trump is thinking along similar lines for NAFTA, with the support of Republican Sen. Chuck Grassley.