ISIS militants besieging swathes of Syria and Iraq have stepped up their propaganda war Thursday, releasing a video purporting to show the beheading of a Kurdish fighter. The three-minute clip, issued by the extremist group's media office, shows 15 hostages alleged to be Kurdish "Peshmerga" forces - a group that has been a crucial bulwark to the ISIS onslaught.

"This video aims at instilling fear in the heart of the American street, to object to Obama's new policy in Iraq and Syria, as much as instilling terror in the heart of the Kurds, who stand as the only effective Iraqi force in combating The Islamic State," according to Laith Alkhouri, a senior analyst at New York-based intelligence consulting firm Flashpoint Global Partners. "Though it's not different from [ISIS’s] modus operandi, it's unique in the fact that the beheaded individual is a Kurd; unlike most recent beheadings, who've mostly been Sunnis, Shiites and Westerners."

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