LONDON (AP) — Former British Prime Minister Tony Blair says the West’s failure to intervene in Syria is to blame for the violent insurgency in neighboring Iraq — not the 2003 invasion that toppled Saddam Hussein.

In an essay issued Sunday, Blair called for Western countries to intervene in Syria, though he did not specify how. He wrote that extremists “have to be countered hard” wherever they are fighting.

Blair led Britain to join the U.S.-led intervention in 2003, and is now a Middle East peace envoy. He rejected as “simply not credible” arguments by critics who claim Iraq would be stable today had the invasion not happened.

Former U.K. ambassador Christopher Meyer said Blair was wrong, and that the campaign against Saddam was a significant reason for the sectarian violence in Iraq.

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