The full advice that Attorney General Lord Goldsmith gave to the prime minister before the Iraq war has been published on the Downing Street website.
Goldsmith's advice hardened within days
The 7 March 2003 advice examines possible doubts and arguments about the legality of the war that were not published at the time.
None of these concerns appeared in the published advice on 17 March.
The key concerns raised are:
1. Whether it was up to the Security Council, not Prime Minister Blair or President Bush, to rule on whether Iraq had broken a UN requirement to disarm.
The issue here is the extent to which member states can interpret a Security Council resolution as a mandate for action without having an unambiguous authorisation from the Council itself.
Lord Goldsmith pointed out that legally it would be stronger if the Council itself made a determination that Iraq had been in "further material breach" of Resolution 1441.
The USA has been arguing for recognition of a broad doctrine to use force to pre-empt danger in the future...this is not a doctrine which, in my opinion, exists or is recognised in international law
Lord Goldsmith, 7 March 2003
This resolution, passed on 8 November 2002, had given Iraq "a final opportunity to comply" with its disarmament obligations.
The attorney general suggested that a court, though which court he meant we do not know, might rule that the Council itself should decide.
The resolution stated that the Council would "consider" the situation if Iraq was reported to be in non-compliance. The attorney general argues that this word was deliberate.
If the Council had required a further decision, i.e. to go to war, it would have said so. Opponents of the war argue the exact opposite, that to "consider" means just that.
2. Whether the wording of Resolution 1441 authorised military action.
The resolution recalls that Iraq has previously been warned of "serious consequences" as a result of its violations.
The attorney general appears to suggest that this falls short of the "all necessary means" wording which, for example, authorised the removal of Iraq from Kuwait in 1991.
3. Whether another Security Council resolution was needed.
This would have been the so-called "second resolution" following up 1441. The attorney general said the "safest legal course" would be to secure the adoption of a further resolution to authorise the use of force.
4. Whether it was enough to rely on previous resolutions to justify war.
Here the issue was whether the US and UK could "revive" the original resolution 678, passed in 1990, which authorised the removal of Iraq from Kuwait.
That resolution also spoke about using all means to "restore international peace and security in the area."
It was followed by resolution 687 which approved a ceasefire and the argument was whether Iraq's "further material breach" mentioned in 1441 permitted those earlier resolutions to be used to enforce "peace and security."
Lord Goldsmith's memo says that "having regard to the negotiating history I have been given and to the arguments of the US Administration," he accepted that a "reasonable case can be made" that resolution 1441 "is capable in principle" of reviving the authority in 678 without a further resolution.
5. Whether Iraq was complying with the inspections.
Lord Goldsmith noted that on the day of his letter, the chief UN inspector Hans Blix had reported progress in that 34 illegal Iraqi missiles had been destroyed and that no weapons of mass destruction had been found.
This raised the issue of whether in fact the UN might eventually find that Iraq had complied with its inspection obligations.
Lord Goldsmith says that the argument about "revived authority" "will only be sustainable if there are strong factual grounds for concluding that Iraq had failed to take the final opportunity.
"In other words, we would need to be able to demonstrate hard evidence of non-compliance and non-cooperation."
The views of the weapons inspectors "will be highly significant in this respect."
In light of their most recent report, "you will have to consider very carefully whether the evidence of non-cooperation and non-compliance by Iraq is sufficiently compelling" to justify that conclusion.
6. American authorisation for war did not apply to Britain.
The attorney general said the US Congress had the previous October granted President Bush the power to go to war with Iraq.
Such authority did not cover a British prime minister and also made it easier for a US president not to press for a second resolution.
7. The actions taken in Kosovo without UN authority did not constitute a precedent.
UK forces took part in military action against Iraq in December 1998 and in Kosovo in 1999 without UN resolutions on the grounds that they were preventing a humanitarian catastrophe.
The attorney general says the international legal basis of these actions was uncertain. There was a "reasonable case" but he could not be confident that a court would agree with this view.
"The doctrine (of overwhelming humanitarian catastrophe) remains controversial. I know of no reason why it would be an appropriate basis for action in present circumstances."
And "it must be recognised that on previous occasions when military action was taken on the basis of a reasonably arguable case, the degree of public and parliamentary scrutiny of the legal issue was nothing as great as it is today."
8. Whether a second resolution could be valid even if there was an "unreasonable veto".
The attorney general says: "I do not believe that there is any basis in law for arguing that there is an implied condition of reasonableness which can be read into the power of veto conferred on the permanent members of the Security Council by the UN Charter."
And, he adds, "it is likely to be difficult on the facts to categorise a French veto as unreasonable."
9. Whether the UK government or its military personnel could be subject to legal action.
Lord Goldsmith warned that "there are a number of ways in which opponents of military action might seek to bring a legal case, internationally or domestically, against the UK, members of the government, or UK military personnel," for example in the International Court of Justice or the International Criminal Court.
He also warned that "given the strength of opposition to military action against Iraq, it would not be surprising if some attempts were made to get a case of some sort off the ground."
And he said that while it was unlikely, "we cannot be certain that they would not succeed."
10. Whether regime change was a justification for war.
The Attorney General warned that "regime change cannot be the objective of military action."
He stated that the use of force will be legal only if it is "proportional", which means that "it must have as its objective the enforcement of the terms of the cease-fire", must be "a proportionate response" to the objective of securing compliance with Iraq's disarmament obligations" and "be limited to what is necessary to achieve that objective."
However, he said that action to remove Saddam Hussein from power could be justified "if it can be demonstrated that such action is a necessary and proportionate measure to secure the disarmament of Iraq."
In broader terms, Lord Goldsmith also expressed scepticism about the US doctrine of "pre-emption".
He said that he was aware that "the USA has been arguing for recognition of a broad doctrine to use force to pre-empt danger in the future.
"If this means more than a right to respond proportionately to an imminent attack (and I understand the doctrine is intended to carry that connotation) this is not a doctrine which, in my opinion, exists or is recognised in international law."
Those, therefore, were the issues raised by Lord Goldsmith on 7 March.
US authorisation did not apply to British troops
Subsequently, he resolved all the doubts he had expressed and gave his approval for the war in an opinion read to the cabinet on 17 March and published as a written answer to a question in the House of Lords.
The cabinet did not see the earlier letter which has only now been published by the government, after it was partially leaked.
The final advice put forward by the attorney general relies on the justification that the original 678 resolution was "revived".
He dismissed the doubts he raised in item number 4 above about it being "difficult" to make this case.
He made the case very succinctly in nine brief paragraphs.
He said that "it is plain" that Iraq had not complied with its obligations under 1441 to cooperate and disarm.
Action was therefore allowed to restore "peace and security" which was the original intention of 678 (allowing the removal of Iraq from Kuwait) and which was only suspended by the ceasefire resolution 687.
As for a second resolution, Lord Goldsmith said: "Resolution 1441 would in terms (i.e., it would have used the exact words) have provided that a further decision of the Security Council to sanction force was required if that had been intended."
All 1441 needed, he claimed, was a discussion of Iraq's failures, not a further decision or resolution.
Of course, those who opposed the war said that a second resolution was needed precisely because the Council did not spell out what should happen.
For opponents, the word "consider" meant just that, a consideration of what to do.
That issue has never been legally resolved.