The UK's justification for the war with Iraq raises issues about disclosure.

The government should have given a full account of the Attorney-General's advice, argues Roger Smith

'An end to Suez or Iraqi adventures,' proclaimed Lord Alexander in his Justice annual lecture at the Law Society earlier this week.

He examined the legal justification for the conflict and concluded that this war was as unjustified in international law as that over Suez.

He said that it is time for the courts to adjudicate on the legality of a prospective war and, in consequence, for the government fully to disclose the legal advice on which it purports to act.

The similarities between Suez and Iraq are disturbing.

Both were instigated in breach of the charter of the United Nations.

Disturbingly, both - at least if as Clare Short claims - were conducted in furtherance of a secret agreement with a foreign power.

Both turned decisively on the strength of the US, though to rather differing effect.

Eisenhower and Dulles backed multilateralism and pulled Eden back; Bush and Rumsfeld, in thrall to neo-conservative unilateralism, egged Blair on.

International law is not a precise tool.

However, three major justifications might be provided for the use by a country of armed force: furtherance of a UN Security Council decision; self-defence, also covered by the UN Charter; and, more controversially, humanitarian reasons - as notably advanced by NATO to justify bombing Serbia to halt ethnic cleansing in Kosovo.

Consideration of self-defence takes us into realms explored by Lord Hutton and, specifically, the '45-minute' claim.

Article 51 of the UN charter authorises the use of force to meet 'armed attack'.

A line of academic thought suggests that, in any event, this gives no justifica-tion for action in anticipation of an attack.

However, the better view is probably that an old doctrine of 'anticipatory self-defence' still exists but with stringent requirements of necessity and proportionality.

This was successfully deployed to justify firing on a US ship, the Caroline, by the British navy during the revolt of French Canada in 1837.

Today, if Iraq really were imminently likely to send weapons of mass destruction to Britain or, for example, Cyprus, then there would remain justification under article 51.

Battlefield nukes, or their chemical or biological equivalents, would not seem to count.

That is the importance of the row over the first government dossier, the one before that dismissed by the Foreign Secretary as 'Horlicks' and generally described as 'dodgy'.

In some ways, it must be acknowledged that the British government commendably sent our troops off to war with more public discussion than any predecessor - it published a summary of the Attorney-General's legal opinion and there was a parliamentary debate.

However, neither was very satisfactory.

The latter was influenced by dossiers, whose reference to weapons of mass destruction has now been somewhat qualified by those that made it.

Lord Goldsmith's opinion was not disclosed in full.

He advanced a tortuous argument that bypassed the obvious meaning of the most recent UN resolutions, manifestly not authorising the use of force, and went back to resolutions of 1990 that authorised invasion 'to bring the invasion and occupation of Kuwait by Iraq to an end'.

However, John Major, prime minister at the time, has been clear about the limits of such authorisation: 'Our mandate from the United Nations was to expel the Iraqis from Kuwait, not to bring down the Iraqi regime.' Two years ago, he accepted: 'To go further than our mandate would have been, arguably, to break international law'.

Thus, the UK did not act in self-defence.

There were humanitarian concerns but they were not advanced as the main reason and did not reach any relevant threshold.

The assertion of an indirect authority by a UN Security Council requires sophistry of the highest order.

The legal basis for war becomes somewhat indistinct.

There are lessons.

First, the UK government was right to accept that it can act only in accordance with international law.

However inconvenient, this is paramount.

Second, the government's full construction of its legal position should, in future, be placed in the public domain.

The Attorney-General merely summarised his advice in a parliamentary answer.

Advice published by the Foreign and Commonwealth Office took analysis no further.

The government relied on convention to prevent full disclosure of the Attorney-General's full advice or advices.

It is time for this constitutional bashfulness to be removed.

On such a crucial issue, the government's view of the law should be exposed to the spotlight of reasoned argument and scholarship.

Furthermore, the time has come to allow the courts to rule on the legality of foreign policy.

Public law has now advanced to a stage where this is a logical next step.

The Master of the Rolls has already indicated the principle in the case of Abbasi v Secretary of State for Commonwealth and Foreign Affairs [2002] EWCA Civ 1598 - earlier this year: '[The] court...

is free to express a view in relation to what it conceives to be a clear breach of international law, particularly in the context of human rights'.

It seems strange that courts to be unable to give rulings on the legality of an act as fundamental as the invasion of another state.

Law cannot just be the docile handmaiden of realpolitik.

Roger Smith is the director of the human rights campaigning group Justice