The world's most important number might be the yield on ten-year American Treasury bonds. The government's cost of borrowing matters for everything from mortgages to corporate bonds. In recent weeks it has yoyoed, as have yields on other countries' bonds. The volatility reflects the increasing risk of an unpleasant economic outcome: high inflation with stagnant growth.

On Wednesday Mark Rutte, NATO's secretary-general, will meet Donald Trump in Washington. He may face a frosty reception. Mr Trump has taken his relationship with the alliance to new lows, after many of its members refused to support his war in Iran. European countries can no longer avoid considering a NATO without America.