Leading article: Iraq: doomed from the start

"We're supposed to learn from the mistakes of history, but we keep making the same mistakes," says Lawrence Colburn, a US veteran who returned to Vietnam to mark the 40th anniversary of the My Lai massacre. Today's anniversary of My Lai and this week's fifth anniversary of the invasion of Iraq allow us to look at the parallels between two disastrous wars.

Of course, Iraq and Vietnam are very different. Some of those who warned against military action in Iraq because it would be "another Vietnam" weakened their case by simplistic analogy. It was never likely that casualties among US and allied forces would be as high, or that they would meet a disciplined guerrilla army. But the mistakes of which Mr Colburn spoke were serious and foreseeable.

Mr Colburn was a member of a three-man helicopter crew that landed in My Lai to stop the killing. US troops, frustrated by their inability to find elusive Viet Cong, had opened fire on civilians. There had been no enemy fire, but 500 men, women and children were killed. Colburn and the anti-war veterans who travelled to Vietnam this weekend say they were distressed to see their comrades in Iraq repeat the error of dehumanising the people they were supposed to be liberating. Early on in the Iraq occupation, a US army officer was filmed by the BBC declaring after a roadside explosion, "this town's gonna pay". A mindset of overwhelming force, indifferent to civilian casualties, led as if on tramlines to torture to Abu Ghraib and the creation of an al-Qa'ida-inspired resistance to foreign troops.

Five years on, the sharpest question is that posed in private by David Miliband before he became Foreign Secretary. If the mistakes of the post-invasion phase had been avoided, was success in Iraq ever possible? It is a question that was asked of Jonathan Powell, Tony Blair's former chief of staff, yesterday. He said that the main mistake was "not understanding quite what we were getting ourselves into". But was it not the responsibility of the Government to know? He said that there was planning, "but it was planning for completely the wrong thing" – water shortages and humanitarian supplies. If only they had known, he said, they would have had more troops and "been faster to secure the streets from random violence".

Mr Powell has a selective memory. Mr Blair was visited by six experts on Iraq in November 2002, led by Professor Sir Lawrence Freedman. Another of the six, Toby Dodge, warned the Prime Minister that "we would be going into a vacuum, where there were no allies to be found, except possibly for the Kurds".

The Independent on Sunday has been steadfast in its view that the invasion of Iraq was a reckless misjudgement that would mean death and destruction for Iraqis and make the world less safe. Some of our rivals have adjusted their uncritical acceptance of Mr Blair's beguiling optimism of five years ago. Others have seized on the reduction of civilian casualties since the "surge" of US troops a year ago as evidence that the situation is being turned round. Welcome as that reduction is, the sober reporting of our correspondent, Patrick Cockburn, puts it in its bleak perspective.

So, among the guilty people that we would name as responsible for the disaster of Iraq, we would include journalists collectively, in Britain and America. In our assessment of the winners and losers from the war we include the media among the latter. Partly, this was because journalists and opponents of the war focused too much on the distraction and legal device of weapons of mass destruction, on which, before the war, little could be proved.

Instead, we should have been asking much more searching questions about what would happen after the invasion. Five years on, it has become much clearer that the answer to Mr Miliband's question is that it would have been incredibly difficult to depose Saddam Hussein without unleashing the forces that led to such massive loss of life. Of course, if the Pentagon had looked ahead and realised that it should keep Saddam's army and the Baathist party structure, some of the bloodletting might have been avoided.

But, even if many more troops had been deployed, it is not certain that they could have secured order. Even if they had treated the human rights of every Iraqi with rigorous respect and fixed the electricity, it would have been hard to avoid the collapse of civil society into sectarianism.

The invasion of Iraq was a doomed enterprise from the start, and we were right to say so.