Tony Blair is nothing if not an optimist. During the past two years, his thesis that the US and Europe must come together to face the great threats of the day - with Britain acting as a transatlantic "bridge" - has been tested almost to destruction. Relations between the US and the European Union were ripped apart by Washington's decision to go to war in Iraq. European governments remain highly suspicious of US intentions towards Iran. And in spite of improvements in the relationship, the list of issues dividing the US and Europe has scarcely diminished: it includes climate change, the lifting of the arms embargo on China and Washington's disdain for multilateral institutions.

Yet Mr Blair's optimism is un- dimmed. As he prepares for a landmark year - one that will see a general election at home and the UK taking on the presidencies of both the Group of Eight leading industrial nations and the EU - he has not given up the goal of rebuilding transatlantic unity.