Tony Blair has blamed violent insurgency in Iraq on the "predictable and malign effect" of the West's failure to intervene in Syria and denied it is linked tot the West's invasion in 2003.
In a renewed call for military action, the former prime minister rejected arguments that his decision to go to war with Iraq was behind the current violence as "bizarre".
In an eight-page essay on his website, he said that unless the international community was prepared to overcome public reluctance and confront the extremists "hard, with force", the consequences would be more serious still.
Mr Blair - now a Middle East peace envoy - said Iraq was "in mortal danger" but pinned the blame on the sectarianism of the Maliki government and the spread of Syria's brutal three-year civil war.
More top news
The 270 victims of the Lockerbie bombing have been remembered today, 26 years to the day that they lost their lives in the air disaster.
Actress Billie Whitelaw, who starred in films including The Omen, has died aged 82.
Scotland's top prosecutor and an FBI director met to discuss the progress of further investigations into the Lockerbie bombing.