LONDON -- The introduction on Jan. 1 of the euro currency into everyday use across 12 countries in one of the world's big three economic zones marks the accomplishment of a 50-year-old project to bring the continent together in partnership and mutual well-being as an alternative to the past periodic states of war.

Even if three of the European Union members -- Britain, Sweden and Denmark -- have chosen to stay aside, leaders in other countries have been busy hailing the replacement of national currencies by euro notes and coins as a further sign that the continent is pulling its weight on the international scene.

The snag is that, striking as it is, the use of the new currency in the shops of Munich, Marseilles, Madrid and Milan looks somewhat irrelevant to the economic challenges for the new year.