The other day a bright young diplomat from China set me an examination question. My first thought was that it sprang from that admirable Chinese trait of searching out enduring patterns in the clatter and chaos of events. Then it struck me that anyone watching the train crashes on either side of the Atlantic should be asking something similar.

The US faces an unsustainable debt burden alongside sustained political paralysis. Strategic decision-making is held hostage to ideological polarisation. Democrats and Republicans may well escape a calamitous default with an 11th-hour deal on the debt ceiling. But a sticking plaster will not bridge the rancorous divide over tax and spending that piles deficit on deficit.

In Europe, the stakes have been higher still. The European Union’s core project, the single currency, has been buckling under the weight of sovereign debt and political discord. Solidarity has been lost to resurgent nationalisms. Germany’s Angela Merkel says that 60-odd years of European integration is under threat. Yet the leader of Europe’s most powerful nation has seemed frozen in the headlights of indecision.