Tony Blair has said that "there was no rush to war", but he had to take into account at least "the possibility of a 9/11 here, in Britain".
He said as prime minister his primary response was to protect his country, and asked people to put themselves in his shoes.
Her added he had made it clear publicly and privately that the UK would stand with the US on the issue of the Iraq War.
But he insists his note to George Bush saying: "I will be with you, whatever" meant he would "be with the USA in dealing with this issue".
Alex Salmond told Peston on Sunday that he was backing the motion because a "verdict" on Blair was needed.
The long-awaited publication of the Chilcot report has raised many questions - we take a look at some of the key issues.
Thursday morning's newspapers were no less critical of Tony Blair than Sir John Chilcot's report into the Iraq war itself.