Now that Boris Johnson has achieved his lifetime ambition to become the UK’s prime minister, the tragicomedy of Brexit is approaching its climax. While the rest of the European Union has viewed this with barely disguised horror, there is good news and bad news in Johnson’s apotheosis.

The bad news is that the “no-deal” withdrawal from the EU that Johnson advocated to win the leadership of the Europhobic Conservative Party could cause a sudden stop in economic activity comparable to the disaster that followed the failure of Lehman Brothers in 2008.