CHILCOT’S bottom line is that Tony Blair exaggerated the case for war. He failed to exhaust peaceful options. Invading Iraq was not the last resort. Warnings were ignored that further terrorism would be unleashed, thus tightening the spiral of violence.

None of this will surprise the brigadier who escorted me down from the rostrum a few years ago at the UK Defence Academy. Neither will it surprise most of his colleagues.

I had just delivered a guest lecture to some 400 officers on the Advanced Command and Staff Course. For the past 18 years, I have been invited to present those being trained for high command with the case for non-violent conflict resolution.

“You’re here to remind us of war’s limits,” the generals, admirals and air marshals have often said. Why? Because most of this generation have now witnessed limitations to what they call “the utility of force”. War alone does not bring peace.

As he escorted me, the brigadier cleared his throat and asked: “Er, tell me, do the politicians ever have you come and say these things?”

“Never,” I replied. “The trouble is, you get the feeling that they can’t believe they’ve made it until blooded in a war.”

I had in mind Lance Price, one of Mr Blair’s spin doctors. The Prime Minister, he had suggested, “was relishing his first blooding” when he authorised the first air strikes against Iraq in 1998.

Despite all the public hand-wringing about acting “with a heavy heart,” Mr Blair had felt it “part of his coming of age as a leader.”

“Yes,” said the brigadier. “I feared that might be the case. Such a pity.”

Another time, another place, and it was one month into the ground war with Iraq. I was at a private dinner with two generals. One subsequently appeared before Chilcot.

As we spoke, his men were on the ground: carrying out orders through the chain of command, killing and starting to get hurt.

“I have not seen the intelligence that Blair claims to have seen,” he told us. “If it turns out that Saddam has no weapons of mass destruction, Blair will have led us up the garden path.”

“But,” I asked. “Would that not make you – a war criminal?”

“That is something I take very seriously,” he replied, adding that he had been personally to see the Attorney General to be assured of the legality of his orders. After all, Nuremberg had seen commanders hanged, just for following orders.

“But you still felt ill at ease,” I said. “So why did you issue the orders? Why did you not resign your commission?”

“Because...” said this soldier, a man whose every fibre was honed to loyalty. “I was placed in a position where I had to make a moral decision. Did I obey my own gut feelings? Or did I obey orders from my own democratically elected Prime Minister?”

That, today, is where Iraq leaves the armed forces. It leaves people like my friend, the general, potentially vulnerable to the International Criminal Court that hears war crimes, and is already examining allegations against British soldiers.

Not so, allegations against Mr Blair.

And why not? Because the law of war – international humanitarian law – currently has powers to tackle right conduct in a war (jus in bello) but not the primary act of aggression – right conduct in going to war (jus ad bellum).

Not until at least 2017 will both axes of war crimes potentially be under the ICC’s jurisdiction; and then, not retrospectively. Meanwhile, only UK jurisdictions have the power to summon Blair and his entourage.

Some commentators have therefore called for the UK to pull out of the ICC if British soldiers are put on trial at The Hague.

However, if anything is to be learned from Iraq, it is that international humanitarian law needs strengthening, not undermining.

Civilised behaviour is the price of civilisation. Chilcot has spoken with verve. The question, now, is how Britain will respond.

Professor Alastair McIntosh, an honorary fellow at the universities of Glasgow and Edinburgh, is an expert in military ethics.

His latest book, Poacher’s Pilgrimage, is published this week by Birlinn and explores the Iraq and Afghan wars in the context of a 12-day walk across the Hebrides.