The declaration of the United Nations secretary-general, Kofi Annan, on the Iraq war was shocking in its simplicity. He described it for the first time as "illegal". No caveats. No equivocation. None of the ambiguity loved by diplomats, especially at UN headquarters.

The shock is in part because Annan is an inherently cautious individual. He has long professed that his role is basically that of a civil servant carrying out the decisions of the UN security council. But he has finally made his stand, angered by the damage the war has done to Iraq, to the international community and to the UN. He has been building up to these outspoken comments. Only days before the invasion of Iraq in March last year, he hinted at his opposition but without going so far as to declare it illegal, only saying that without a second UN resolution the "war's legitimacy will be questioned and the support for it will be diminished".

In September, he returned to this theme, saying pre-emptive strikes "could set precedents for the proliferation of the unilateral and lawless use of force". He finally left all restraint behind in an interview broadcast by the BBC on Wednesday night in which he concluded: "From our point of view and from the charter point of view, it was illegal."

His verdict undercuts the argument pursued relentlessly by George Bush and Tony Blair that the war had UN approval. Blair cites as justification two Security Council resolutions from the aftermath of the 1991 Gulf war and the one agreed after much tortuous negotiation in 2002, even though it did not warn explicitly of war if Iraq failed to disarm, only of "serious consequences". Annan said on Wednesday this was not enough: a second resolution explicitly authorizing war was needed.

Both the US and British governments have a tendency to treat the run-up to the war as history. This is especially so in Britain where the government argues that the issues have been gone over exhaustively in the Hutton and Butler inquiries. Weary ministers say that whatever the rights and wrongs of going to war, it is time to address the problems facing Iraq now.

The UN charter is perfectly clear in permitting force in only two circumstances: the first in self-defence and the second when the security council authorizes action to counter a threat, usually one regarded as imminent. Neither was the case in Iraq.

Bush personally and Blair through his press officer on Friday continued to insist that the case for war was legal. If Blair is so sure of this, it is time for him to publish the legal advice he received at the time from the attorney general in its entirety so that people can judge for themselves.

Blair would like to see the UN take on a bigger role in Iraq but Annan is resistant, partly because of the bombing of the UN headquarters last year and partly, according to one of his advisers, because he does not feel an obligation to sort a mess of someone else's making.

The carnage on Iraq's streets shows no sign of lessening, and if the security situation does not improve, there is doubt, as Annan hinted, over the feasibility of holding the country's first democratic election in January as planned. There was a brief hope when the US handed over to the interim Iraq government in June that the worst might be over, but since then there has been the siege of Najaf and this week, which has proved to be one of the bloodiest yet. Civil war and fragmentation of the country remain possible. While Annan's verdict on the war is welcome, the pity is that he did not have the courage to make it last year, before the US and Britain embarked on war.-Dawn/The Guardian News Service.