British democracy was once widely seen as a model for others to follow. But it has now sunk into its deepest crisis in living memory. At stake is not only whether the United Kingdom crashes out of the European Union without an exit deal, but also how far a country once famed for stability and moderation descends into political civil war.

Prime Minister Boris Johnson seems determined to take the U.K. out of the EU on Oct. 31 at any cost. The chances of a chaotic no-deal Brexit increased dramatically on Aug. 28, when Johnson moved to suspend the U.K. Parliament for five weeks between mid-September and Oct. 14. It will now be much harder — but not impossible — for his parliamentary opponents to thwart him.

Johnson claims that he wants a deal, but that the threat of leaving without one is needed to force the EU to compromise. In his view, curtailing Parliament's ability to block a no-deal Brexit was necessary to make the threat credible.