Four years ago this week I was kidnapped in Baghdad. My trip to Iraq had been motivated by frustration at the government's deafness to all voices of reasoned opposition to the war in Iraq. I went to meet Iraqis to reassure them that most people in Britain did not regard them as enemies. Today, the lead-up to that war is back in the spotlight with the Chilcot inquiry. This is more than just an academic exercise to many. Anyone – in Britain, Iraq or elsewhere – who had a relative killed in the conflict will feel an intense personal need to discover the truth. They will be listening to testimony that appears to gravely undermine the official justification for going to war. They will want to learn the reaction by the then government to the advice of Middle East diplomats who knew about the conflicts within Iraqi society, conflicts that Saddam had suppressed but were always likely to explode on his removal. If you are going to war, ignorance of the probable effects on the country in the aftermath is inexcusable. Why else do you have a large diplomatic and intelligence force in the area?

I witnessed how much resentment was created by the revenge attacks of coalition forces on Iraqi towns and their apparent disregard for civilian lives. All our captors had suffered the loss of relatives, homes or jobs in the onslaught on Falluja. And, as they asked Jim Loney, the Canadian peaceworker who was also held hostage, "If the Americans had invaded and occupied your country, would you not have resisted them by all means at your disposal?" I am almost surprised that we were treated so moderately by our captors – apart, that is, from the tragic, largely unexplained, decision to kill Tom Fox, the American Quaker. Their opinion was that the coalition forces had deliberately stirred up the antipathies between Shia, Sunni and Kurd peoples.

On our few visits around Baghdad before being kidnapped we witnessed the effects of the war on decaying radiotherapy treatment sources and of the "diversion" of funds away from a vital infrastructure facility – a power station. Many Iraqis said life had been easier under Saddam because he had restored vital services within a few months of the end of the Gulf war.

At a Chaldean Catholic church we met the priest and a group of young people. The church building had been damaged by a bomb earlier in the year. He explained how many of his congregation had fled Baghdad or moved to neighbouring countries. When I contacted him after our release he told me that most of the children had been sent away from Baghdad by their parents, to live in refuge. The priest himself had been kidnapped and beaten before release. Little wonder that one impact of a war carried out by "Christian" forces has been the severe depletion of the country's Christian population.

Most of my recent contacts with Iraqis in Britain indicate that in their view the prolonged occupation is exacerbating the situation. Although much liberal opinion among the British is that we have a duty to stay until the Iraqis have had a chance to put right the damage we have done to their country, these people feel that our continued presence reminds the population of the brutality of the invasion and occupation and that, as in the past, they can eventually solve their own problems.

I hope the Chilcot inquiry will listen to stories from British servicemen and their families. But it would be a tragedy if the dreadful consequences of the war on the millions of men, women and children that make up the villages, towns and cities of Iraq go unheard.

As the evidence about the origins of the war emerges from the Whitehall mandarins it must cause even deeper resentment among those who lost relatives in Iraq – I only lost a few months of my life – and it is difficult to see why Tony Blair and George Bush are not as culpable for the killing of Iraqi citizens as many who have appeared for similar crimes before the court at The Hague.