S o Tony Blair has given up trying to convince people that the war in Iraq was right.
In a BBC Newsnight interview this week he said: What I have tried to persuade people of now is to understand how complex a decision it was because if we don't understand that we won't take the right decision about a series of these types of problems that will arise over the next few years.
Mr Blair also said that although the outcome in Iraq had not been what I hoped for it is much better than if Saddam Hussein, who he described as 20 times worse than Assad of Syria, had remained in power.
We have to wait for the Chilcot report, now promised for later this year, for the full detail of the way Britain's decision to join the United States in invading Iraq was made.
Many people think it was not complex at all -- President George W Bush was determined to depose Saddam Hussein and Tony Blair had committed Britain to supporting him despite contrary advice from many sources and in the British cabinet, and without a United Nations mandate.
The excuse was the non-existent weapons of mass destruction.
Mr Blair is right to think we need to understand how to take correct decisions in future crises but the Iraq lesson does not teach us that at all.