Kurdish peshmerga troops participate in an intensive security deployment against Islamic State militants on the front line in KhazerThrough Raheem Salman and Isabel Coles BAGHDAD/ARBIL Iraq (Reuters) – U.S. warplanes bombed Islamist fighters marching on Iraq's Kurdish capital on Friday after President Barack Obama mentioned Washington must act to forestall "genocide". Islamic State warring parties, who’ve beheaded and crucified captives in their power to eradicate unbelievers, have advanced to inside a 1/2 hour's drive of Arbil, capital of Iraq's Kurdish area and a hub for U.S. oil firms.