A gale of pessimism is blowing through Europe. No part of the European Union is sheltered from the global economic downturn, but its newest member states are the most vulnerable. Fears about eastern Europe’s banking sector sent currency and stock markets plunging this week. How the EU comes to the eastern members’ aid will show whether it is a union worthy of the name. Sadly, its most powerful leaders seem indifferent to what is at stake. Their ever more provocative flirtation with protectionism could undo the historic achievements of the European project.

The EU’s founders, shocked and sobered by the calamitous consequences of protectionism and nationalism in the 1930s, sought, if not entirely to remove national rivalries, at least to temper them through mutual interest. Their vision prevailed, and stability and prosperity spread as new countries chose to pool their sovereignty with their neighbours. The biggest triumphs have come over the past two decades with the establishment of a single market, the creation of a single currency, and the willingness to embrace the countries communism had cut off from the west. Adopt our ways, the EU said, and you will share our prosperity and freedom. Eastern Europe responded eagerly.