It's a slick production with a nefarious goal: A 55-minute video released by ISIS, praising its victories and warning the United States from getting in the way of its goal to create an Islamic caliphate in parts of Iraq and Syria. It's propaganda, terrorism experts say. A recruitment video aimed at English speakers. But the U.S. intelligence community is focused on one jihadist who appears briefly at the end of the video. The ISIS fighter, who speaks perfect English with a North American accent, is shown orchestrating the mass execution of a group of men. It is too early to know if this militant hails from North America, or maybe spent some time there, or what his exact story might be. But the intelligence community is already analyzing the video in an attempt to identify the man's origin, a U.S. official told CNN. It is too early to tell where his dialect is from, the official said. In the video titled Flames of War, the jihadist first appears speaking Arabic in a classical dialect and with the ease of a native Arabic speaker, CNN terrorism analyst Paul Cruickshank said. But the ISIS fighter -- who is masked and wearing a camouflage uniform -- seamlessly switches to English. There are a number of men digging a ditch behind him. The jihadist claims they are Syrian soldiers assigned to a 17th Division military base near the Syrian city of Raqqa, and who now, after an ISIS