When Britain joined what was the European Economic Community, Prime Minister Edward Heath told diplomats from Australia, Canada and New Zealand over dinner that Europe would become a superpower and put the United States in the shade.

The Canadian envoy was brave enough to challenge Heath but when his guests had left, the Conservative prime minister turned to an aide and said: "The poor old Canadian. He doesn't get it, does he?"

Heath's words sound at best naive nearly four decades later.

The unity of the European Union is being sorely tested by a debt crisis in Greece and the economic fragility of other countries.

It took the EU weeks to agree on a multi-billion euro aid package for Athens and it has still not managed to calm financial markets. Its ability to prevent contagion to other countries and hold the euro zone together is in question.

Far from becoming a superpower, the 27-state group that grew out of the EEC is struggling to prevent itself sliding down the world rankings.

Heath would have winced to hear the answer given by Diego Lopez Garrido, Spain's secretary of state for European affairs, when he was asked last month about the EU's failure to take decisions more quickly.

"The European Union is not the United States. We are 27 states, not one state," he said.

Heath's reasoning for joining the bloc was that the only way Europe could have clout in a world of superpowers was if it could unite politically.

The EU's founders set their sights on ever closer political, economic and monetary union but the EU has often failed to speak with one voice, a flaw highlighted by recent crises.

Germany has increasingly been made the scapegoat for holding out against emergency loans for Greece because its voters oppose bailing out a nation they regard as profligate and less hard working. Its image as a force for European solidarity has been tarnished.

But today's European leaders do not have the same emotional commitment to political union as predecessors such as the former German and French leaders, Helmut Kohl and President Mitterrand.

They survived the Second World War, when their countries were enemies, and were united in the desire to prevent another war.

The fear of Moscow that united West Europeans during the Cold War ended with the collapse the Soviet Union, even if some concerns have now been revived. Reunification firmly established Germany as Europe's most powerful state.

At the heart of the Union, something is rotten. French President Nicolas Sarkozy and German Chancellor Angela Merkel have failed to click, and a lack of a common vision means the EU engine is at best stuttering.

EU experts are erring on the gloomy side but say don't write off the Union just yet.

"I don't have a crystal ball. We're at a tipping point. We still have leverage and potential if we get our act together though I don't see much of that," said Ulrike Guerot of the European Council on Foreign Relations think tank. – Reuters