In the winter of 2002–03 those of us who write about politics in Britain were in no doubt our country would sooner rather than later engage in a military action against Saddam Hussein and his regime in Iraq. We were less clear about how it would come about.

The Conservative opposition in parliament was fervently for war, almost unanimously, but was numerically small after two landslide defeats. The Labour Party seemed largely against it, with the exception of those whose continuance in ministerial office depended on supporting Tony Blair. Many others still harboured ambitions to serve under a prime minister who was not likely to leave office too soon, and did not want the black mark against them.

But a large group of disaffected backbenchers — not all of them of the old left, but mostly from there — did not like the way Blair was leading them. They were people of entrenched anti-Americanism dating from the Vietnam era, and they harboured a specific animus against George W. Bush, whom they regarded not merely as unpleasantly right-wing (the term “neocon” was only just coming into currency in Britain then) but also distressingly stupid. They had watched Blair cosying up to him with disdain, distaste, and, eventually dread.

They, like some of the right, saw Blair as unattractively sycophantic in his relations with America: he had enjoyed a political love-affair with Bill Clinton for almost the first four years of his premiership, but he and Bush were thought to have little in common when it came to doctrine or ideology. They did not buy Blair’s line that the security of Great Britain depended on standing shoulder to shoulder with America: they thought he liked to be filmed and photographed with the president of the United States — whoever he might be — for the glamour and status it bestowed on him as the prime minister of an ally. There was probably truth in both interpretations.

When Bush told Saddam on 17 March 2003 that he had 48 hours to surrender power or face a military assault, Blair’s hand was forced. Under the British constitution a declaration of war or the use of military force can be undertaken without recourse to a vote in parliament: it is one of the so-called royal prerogatives that a prime minister can exercise on behalf of the monarch. To have committed British forces without parliamentary approval would have ended Blair’s political career on the spot, such was the feeling of his own party about the wrongness of Britain engaging with Iraq in this way as America’s sidekick.

On 18 March a debate was held in the House of Commons. A prolix motion argued that the only hope of peace in the Middle East was to have Saddam removed from power, not least because he had ridden roughshod over various United Nations resolutions, and the United Nations showed little prospect of agreeing on punitive action. It took for granted that Saddam had weapons of mass destruction, and that the United Kingdom “should use all means necessary” to ensure their removal. The prime minister used what has become known as the “dodgy dossier” of claims about the scale and effectiveness of Iraq’s weapons of mass destruction — notably chemical weapons — to argue the case for Britain to intervene.

An attempt to amend the motion to say the case for war had not yet been made was defeated by 396 to 217 votes; the motion itself was then passed by 412 to 149, with Labour dissidents being outnumbered by Conservatives supporting the government. Robin Cook, the Leader of the House of Commons and a former foreign secretary, resigned. Blair’s reputation has never recovered from the apparent non-existence of WMDs; an inquiry, summoned five years ago by his successor as Labour prime minister Gordon Brown, has still not reported; we still don’t know whether Blair cynically lied or exaggerated, or whether he was woefully misinformed by the intelligence services, or whether others in his press operation fed in some lies and exaggerations to put lead in his pencil — what was called at the time “sexing up” the dossier. Either way, British troops were committed the following day and the rest, as the cliché goes, is history.

The lessons for Britain, 11 or more years on, and unaided so far by the findings of the formal inquiry, seem to abound.

The first lesson would seem to be to tell the truth — that’s pretty fundamental. When you are committing a nation to war it cannot be on a false prospectus. It is not merely the lives of your own citizens that will be at issue, but also those of the country you are waging war against. If you kill thousands, or hundreds of thousands, of them for what turns out to be no good reason at all, that is little short of a war crime: something opponents of Blair and Bush have argued for the last 11 years, in the hope of having them arraigned in some international court.

To be sure you, as a potential war leader, are telling the truth, you have to have absolute confidence in the information supplied to you by your foreign and security services. You need, therefore, to be sure that the people you appoint to run those services are utterly reliable. You must test and question every point they put to you, and test them again; and you must not exaggerate, in justifying yourself, anything they have told you.

The second is to be able to make a rigorous assessment of what the national interest is, and what it dictates in circumstances such as Britain was in during 2003. This to an extent depends on the first point: you can only make that assessment if you have completely reliable information upon which to base it. But you then have to exercise a statesperson’s judgement about whether, even if everything you believe to be true is true, that state of affairs merits taking your country to war, and expending blood and treasure.

Until the inquiry into what really happens in 2003 is published — the latest delay, we are told, is over the publication of communications between Blair and Bush — we are to an extent flying blind. However, the supposition is this: that without claiming there were WMDs ready to be launched against the west, Blair would not have frightened enough Labour MPs into supporting him in the vote to allow his position to remain safe, and therefore the claims were “sexed up.”

If this is true it is more than disgraceful, because of the lives subsequently lost on all sides and the long-term destabilisation that ensued. Without the threat of WMDs, it is hard to see how the British national interest was at stake and therefore how our part in the American assault on Iraq can be justified. If Bush thought that he could avenge 9/11 by obliterating Saddam’s regime, that was his call, but if all this amounted to was an act of revenge, rather than ensuring the security of the United Kingdom, then Britain should have had no part in it.

The third is to treat the men and women of your armed forces with respect. Too many of our service personnel were killed in Iraq because of defective kit and equipment. Nor have those who were bereaved by this misjudgement, or who still suffer physical and psychological damage because of it, always been treated with the compassion and care such sacrifice would normally be considered to merit. There is something called the “military covenant” in Britain that is supposed to ensure this. It doesn’t. Instead, we chip away at our armed forces to save money with the result that continuing care and support dwindles and the existing forces are overstretched and under-equipped. If you are going to fight wars, be prepared to spend money on them and on dealing with their aftermath.

The fourth is to conduct your diplomacy with allies on the basis of honesty and integrity, but also to know when it is wise to disagree. The North Atlantic alliance would not have ended had Britain refused to join in the expedition to Iraq. Indeed, it might have been strengthened, by making Bush realise that Britain was a mature partner and not a poodle, and perhaps causing him to think again before he decided to act without such an important ally. You can be friends with people without always fighting their wars with them.

No one in Britain underestimates the trauma caused to America by 9/11, but it would have been more sensible for Blair to act as Bush’s bereavement counsellor rather than as his assistant armourer in the months that followed. There is nothing gutless about advising caution when the consequences of action are so much in doubt, because on such judgements hinge the probity and integrity of nations.

The fifth is to decide where you stand in relation to international institutions. Britain went along with the United Nations for years, then decided to act in a freelance fashion with the United States to implement UN resolutions that the United Nations lacked the ability to follow through with. That change of the rules in mid-game was alarming and put the United States and Britain morally in the wrong. If the UN was not giving satisfaction then the right thing to do was to seek to change it and, if that appeared impossible, to decide whether or not continued membership of such a hamstrung group was feasible. Dining à la carte from the rulebook cannot be an option. The purpose of such institutions is to anchor the nations who subscribe to it to a code of conduct. It ill behoves anyone to break the code in so casual a fashion as happened in 2003, and can only have undermined the institution long-term.

The sixth is, if you become embroiled in a war, have an exit strategy. This includes devising what form of government you will bequeath to a conquered nation when you get out. This was the most shameful dereliction on the part of the allies when they invaded Iraq. George H.W. Bush understood in 1991 that by leaving a government in place, Iraq would not subside into anarchy. Since his son wanted to oust the regime, that was not an option in 2003. 

Yet the allies had no serious plan for what would replace Saddam, not least because the Americans in particular seemed to have no conception of what sort of nation it was that would have to be governed. There was no George Kennan when America needed him. If all other considerations are fulfilled and the national interest dictates that an invasion is necessary, a nation should undertake that only when it is clear what happens next. There is a similar problem now in Afghanistan, where the Taliban have simply re-entered parts of the country previously occupied by British troops. An act of revenge or punishment against another country may bring immediate gratification, but it is irresponsible and, indeed, fatal not to consider the consequences.

There may be other lessons. But perhaps the most important is that of telling the truth. If Blair had been utterly honest with parliament and the British people, his country’s long and costly involvement in the war would probably never have happened. Once it had, being honest with the public about the scale of the misjudgement and of the continuing consequences might have forced him out of office, but it would have preserved a little of his, and his country’s reputation. The ultimate lesson is that if you don’t need to have a war, don’t.