Using its own version of "soft" and "hard" power, the self pro-claimed Islamic State of Iraq and Sham (ISIS) is crushing resistance across northern Iraq so successfully that its promise to march on Baghdad may no longer be unrealistic bravado.While conventional states try to win hearts and minds abroad before necessarily resorting to military force, the militant group is also achieving its aims by psychological means - backed up by a reputation for extreme violence.The ISIS, which in June captured a vast stretch of territory in the north including the largest city Mosul, used this strategy when its fighters met armed resistance from the town of al-Alam for 13 days running.They kidnapped 30 local families and rang up the town's most influential citizens with a simple message about the hostages: "You know their destiny if you don't let us take over the town." Within hours, tribesmen and local leaders caved in to save the families. Weeks later, only a few masked gunmen guard checkpoints surrounding al-Alam at night, so comfortable is the ISIS in its control through fear. "One hundred percent of people are angry that the ISIS is here but there is nothing we can do," said a scared resident who spoke by telephone on condition of anonymity.