Mr Tony Blair has chosen to make his country's close relations with the United States the main feature of his foreign policy, in many respects the defining aspect of his prime ministership. His speech to the joint Houses of Congress reaffirmed these themes of transatlantic partnership at a politically difficult time for him and President Bush over the war in Iraq and its post-war occupation by US and British forces.
Just how acutely Mr Blair's reputation is on the line domestically over the issue was confirmed by the death yesterday of Dr David Kelly, a scientific expert on weapons of mass destruction and Iraq. He was named by the government as the possible source of a contested story run by the BBC, saying Mr Blair's office exaggerated the threat of such weapons substantially beyond the evaluation of intelligence sources.
If it emerges that Dr Kelly was hounded as the source of the report (which he denied) there would be serious consequences for Mr Blair and his government, since they have staked their credibility on denying the report. At the very least it demands an independent investigation with greater authority than the parliamentary one which has so far dealt with the issue. The rapidity with which Mr Blair has ordered an independent judicial inquiry into the circumstances leading up to Dr Kelly's death indicates how seriously he views matters.
The intelligence sources and their reliability are at the centre of the difficulties faced by the US and British governments in justifying the decision to go to war. Reports alleging that Iraq attempted to purchase from Niger uranium to make nuclear weapons were forged but were nevertheless used by both Mr Blair and Mr Bush to demonstrate the threat posed by Saddam Hussein's regime. In his speech Mr Blair said history would forgive them if they were wrong about this link between weapons of mass destruction and terrorism, since "we will have destroyed a threat that, at its least, is responsible for inhuman carnage and suffering". Alternatively, if they were right and did not act history would not forgive them for not giving leadership in the face of such a menace.
It has been said perceptively that whereas US leaders and people believe themselves to be at war following the terrorist attacks on New York and Washington on September 11th 2001, Europeans have no such feeling of threat. That psychological difference goes far to explain their differing approach towards the war in Iraq. Mr Blair has famously sought to bridge the gap by pledging British support for the US while seeking to modify its temptation to opt for unilateralism or isolation.
His warning that transatlantic relations must be multilateral not competitive and his call for the US to listen to and not command its European partners are well taken. Unless relations are conducted on an equal footing reflecting their changing status they will drift apart. If the US wants greater European involvement in stabilising Iraq it must be ready to pay the political price of giving the UN much greater authority there. Mr Blair's international standing depends on recognising this reality.