The concept of a 'just war' has been much debated for centuries in the West: what circumstances allow a Christian to put aside God's commandment 'Thou shall not kill?'

This debate resurfaced briefly in the weeks leading up to the war on Iraq last year. Not so much in the biblical context, but in the discussion of whether a second UN Security Council resolution was necessary to authorize the US-led coalition to invade Iraq. In the event, given the doubts of most SC members, Bush and Blair proceeded to go ahead virtually on their own.

Almost a year since the invasion, the chickens are coming home to roost, at least for Tony Blair. Each time he tries to 'draw a line' under Iraq and move ahead with his domestic agenda, a fresh political embarrassment throws him off balance.

Each of these rows relates, in one way or another, to the wider question of the legality of the Iraq war. Some writers have even suggested that Blair might be tried as a war criminal if it is established that he deliberately misled parliament.

In the United States, too, this question is having an increasing resonance in the presidential election as Bush's popularity ratings drop. The Democratic nomination process has put Iraq at the centre of the debate, with the Vietnam war dodger, George Bush, being lambasted for rushing into war and putting young Americans in harm's way when there might have been no need for it.

Of course, had any weapons of mass destruction been found, this would all have been academic and the warmongers would have been fully justified. In the event, as the security and political situation in Iraq continue to deteriorate, both Bush and Blair find themselves on the defensive.

With the American elections coming up in November and parliamentary elections in Britain due by the summer of next year, the question of 'trust' is dogging both leaders at every step.

All this goes to show, yet again, that there is no such thing as a free lunch. It now seems that very soon after 9/11, the Americans had decided to attack Iraq. When this decision was conveyed to Blair, he committed Britain's support. Both governments then proceeded to 'sex up' the intelligence available on Iraq's mythical WMDs to sell the war to their people.

The war was an easier sell in America since Bush used his people's anger over 9/11 and their gullibility to assure them that somehow, Saddam Hussein was hand in glove with Al Qaeda, and was capable of handing over some of his dreaded WMDs to Osama bin Laden.

But the British electorate is better informed than their American cousins, apart from being fairly anti-Bush. Also, the Labour Party was itself divided on war. Hence the opposition to going in without UN cover was much stronger in Britain than it was in the US.

Now barely a day passes without some fresh revelation to remind the people in Britain and America that they were duped into supporting their governments. Inquiries have been set up in both countries to establish why such a major intelligence failure took place. However, although this exercise has been forced by David Kay's admission that there are 'probably no significant WMDs in Iraq', people see it as an eyewash.

It is now emerging that there never was any clear-cut evidence of WMDs to start with. Both the CIA and MI6 had hedged their estimates with qualifications, but politicians hyped up these careful approximations to make their case. Colin Powell, to his everlasting disgrace, made a detailed presentation at the UN giving all kinds of spurious information.

A year later, the Americans and Brits are no longer even pretending to look for the non-existent WMDs, and the finger-pointing has begun. While politicians are blaming intelligence agencies, the latter have quietly made it clear to the press that they never portrayed Iraq as the pressing threat it was made out to be by Bush and Blair.

This ongoing debate and its implication for the political future of the two leaders is another reminder of the limits of power. One aspect of this is the evidence of military over stretch that was already before us.

With the Iraqi underground putting up a vigorous resistance to American troops, the overbearing might of the sole superpower has been effectively checkmated: they are in occupation without being in control.

The ghastly attacks on Ashura processions in Iraq are a grim reminder of how destabilizing the occupation is. The American blueprint for post-Saddam Iraq is being threatened before it is in place.

If, as now seems very possible, the war on Iraq does ultimately drag down the two leaders responsible for it, the future of the whole doctrine of pre-emptive war will be called into question. After witnessing two powerful politicians defeated and disgraced, which president or prime minister will advocate going to war unless directly threatened?

After 9/11, the cabal of neo-conservative zealots had vigorously pushed for the right to attack states and groups before America was attacked. Although this flew in the face of international law and the UN charter, America's muscular patriots claimed this right to prevent the terrorists from ever threatening their security again.

The American attack on Afghanistan was not seriously questioned because of the clear link between Al Qaeda and 9/11, and the Taliban's sheltering of Osama bin Laden and his gang.

The world saw the hammering of that benighted country as an exercise of the right of self-defence, albeit a very one-sided one. Also, many of us saw it as the Taliban getting their just desserts for their awful rule.

But nobody with any idea of world affairs saw Saddam Hussein, murderous as he undoubtedly was, as being connected in any way with 9/11. So an attack on Iraq needed proof and legality in a way an attack on Afghanistan did not. Legality was denied the coalition by a UN that insisted that the inspectors be given enough time to complete their work. And now the proof of WMDs turns out to be concocted, leaving Bush and Blair out on a limb.

Thus the suffering of the people of Iraq might end up doing some good: both the military and the politicians in the only superpower will think long and hard the next time before rushing into war. The other thing to have emerged from this whole painful mess is the fact that sooner or later, democracies do punish leaders who lie to their people.