THE Prime Minister has fired another salvo in his growing war of words with US presidential hopeful Barack Obama, saying the senator had dodged his criticism of his Iraq withdrawal plan. Senator Obama today challenged John Howard to commit another 20,000 Australian troops to Iraq after the Prime Minister said his call to bring American troops home by March 2008 would be a victory for al Qaeda in Iraq, who would be hoping for a Democrat win in next year's presidential election. The US senator accused Mr Howard of "empty rhetoric" in his criticism of his stand, as Australia has...