They are also vowing to behead a second American journalist, Steven Sotloff, unless Obama calls off airstrikes.

Via The Blaze:

A new video posted online Tuesday purportedly shows Islamic State militants beheading an American journalist.

The nearly five minute video, titled “A Message to America,” depicts a man believed to be missing photojournalist James Foley being beheaded by a militant.

The video opens with a message from the Islamic State, attacking President Barack Obama for recently directing airstrikes against the terror group.

“Obama authorizes military operations against the Islamic State effectively placing America upon a slippery slope towards a new war front against Muslims,” the video said.

Then the shot pans over to Foley, who speaks into the camera.

“I call on my friends, family and loved ones to rise up against my real killers: the U.S. government,” Foley said in the video.

The 40-year-old is then beheaded by the masked militant. A graphic image of his decapitated head is shown sitting on his body.

At the conclusion of the video, an image of journalist Steven Sotloff is shown.

“The life of this American citizen, Obama, depends on your next decision,” a voice said.

Update: Not even a little bit surprised.

Via NYDN:

An American freelance photojournalist missing since being abducted in Syria some 22 months ago was apparently beheaded by an Islamic State militant in a graphic video released Tuesday.

Titled “A Message to America,” the gruesome clip shows a masked militant saw away at the neck of James Wright Foley, a 40-year-old New Hampshire native captured in Binesh, Syria on Thanksgiving Day 2012. […]

The militant, speaking English with what appears to a British accent, threatens America and President Obama, directly after Foley finishes speaking.

“So any attempt by you, Obama, to deny the Muslims their rights of living in safety under the Islamic caliphate will result in the bloodshed of your people,” the man says, gesturing with a knife he then uses to behead Foley.