Obama warns Islamic State leaders 'you are next'

US President Barack Obama voiced renewed determination to destroy the Islamic State group Monday, vowing to win back territory in the Middle East and kill the group's leaders. Sounding a notably more strident tone, Obama said that the United States and its allies were taking the fight to Islamic State in Iraq and Syria. "We are hitting them harder than ever," said Obama, in a second address following a seemingly IS-influenced attack in San Bernardino that has raised questions about his strategy.