Amnesty International describes the curent state of play:

Carnage and despair in Iraq

Five years after the US-led invasion of Iraq, the country is still in disarray. The human rights situation is disastrous, a climate of impunity has prevailed, the economy is in tatters and the refugee crisis continues to escalate.

Seumas Milne sums it up brilliantly in The Guardian:

There must be a reckoning for this day of infamy

The problem in Iraq, we’re now told, was a lack of preparation, or the wrong kind of planning, or mistakes in implementation. If only, say the neocons, we had put our man Ahmad Chalabi in charge from the start, the Iraqis wouldn’t have felt so humiliated. If only we hadn’t dissolved the army, the pragmatists insist, the insurgency would never have taken off. If only the Brits had been running the show, mutter the old Whitehall hands, all would have been different. The problem, it turns out, was not the invasion and occupation of a sovereign Arab oil state on a tide of official deceit, but the way it was carried out…

…For the future, so long as the disaster of Iraq is put down to mistakes or lack of planning, the real lessons will not be learned, but repeated – as appears to be happening now in Afghanistan. Gordon Brown has at last promised a full Iraq inquiry when British troops are no longer in the firing line. But any more delay to a proper accounting of what has taken place – including, as the Liberal Democrat leader Nick Clegg said at the weekend, the nature of the US-British relationship – will only further corrode the political system. The disaster of Iraq has at least had the effect of demonstrating the limits of imperial power and restraining further US attacks. The danger is, however, that next time they’ll just try and do it differently – without the mistakes.