As the eighth round of trade talks with the European Union is about to start, U.K. government officials from the chief trade negotiator, David Frost, to Foreign Secretary Dominic Raab have put out the word that Britain is ready to walk away. To underscore the point, Boris Johnson is setting a deal deadline of Oct. 15.

The prime minister is also threatening something much more serious. According to a Financial Times report on Sunday, the government will introduce legislation this week contravening the international treaty that sealed Britain’s EU exit. If Johnson follows through with the new law, which would weaken the Brexit Withdrawal Agreement’s provisions on Northern Ireland, he will probably scupper chances of a trade deal and undermine Britain’s international standing and credibility. At a time when his error-ridden COVID policies are under fire, it seems an odd gamble.

"This would be a very unwise way to proceed,” tweeted Simon Coveney, Ireland’s foreign and defense minister. That’s diplomat speak for, "Are you out of your mind?” The idea of effectively ripping up the Northern Ireland Protocol is so extreme it’s tempting to dismiss the suggestion as an empty threat. And yet, even the posturing is worrying.