Former U.N. Secretary-General Kofi Annan says former British Prime Minister Tony Blair could have averted the invasion of Iraq in 2003. Annan, in an interview with The Times of London, said he wonders what would have happened if Blair had told former President George W. Bush he would not go to war without a second U.N. resolution. \"I really think it could have stopped the war,\" he said. \"It would have given the Americans a pause. It would have given them a very serious pause to think it through. ... All this would have raised a question: \'Do we go this alone?\'\" Annan is promoting his memoirs, \"Interventions -- A Life in War and Peace,\" The Guardian said. He wrote the book with Nader Mousavizadeh, who served as his special assistant at the United Nations. In the book, Annan describes a 2005 conversation with Blair about the conflict between Israel and the Lebanese group Hezbollah. He says Blair perceived \"a meta-conflict between modernity and the medieval, between tolerant secularism and radical Islam.\" \"This was not the Blair with whom I had agreed so passionately about the moral necessity of a humanitarian intervention to halt the Serbian attacks on the Kosovar Albanians in 1999 ... Something had changed in Blair, and with it, I felt, his ability to act as a credible mediator,\" he said.