"Jihad John" has apparently struck again. The British born terrorist is seen in another beheading video with the victim, Alan Henning. As ISIS had done in previous videos, they trotted out their next target. This time, it's an American named Peter Kassig.

Associated Press:

"Obama, you have started your aerial bombardment of Sham (Syria), which keeps on striking our people, so it is only right that we continue to strike the necks of your people," the masked militant in the video said.

National Security Council Spokesperson Caitlin Hayden confirmed that Kassig was held by Islamic State militants.

"At this point we have no reason to doubt the authenticity of the video released earlier today. We will continue to use every tool at our disposal -- military, diplomatic, law enforcement and intelligence - to try to bring Peter home to his family," Hayden said in a statement Friday night.

The Associated Press could not immediately verify the video's authenticity, though it was released in the same manner as other Islamic State group videos and the masked militant sounded similar to the one who carried out the other slayings.

In a statement, the British Foreign Office said it was working to verify the video.

"If true, this is a further disgusting murder," the statement read. "We are offering the family every support possible; they ask to be left alone at this time."

Britain has been supporting U.S. military efforts against the Islamic State group by using British forces to help with logistics and intelligence gathering, as well as recently taking part in airstrikes in Iraq. The Internet video released Friday begins with a news clip announcing British strikes against the Islamic State group.

British Prime Minister David Cameron said Henning's apparent slaying showed "how barbaric and repulsive these terrorists are."

"Alan had gone to Syria to help get aid to people of all faiths in their hour of need," Cameron said in a statement. "The fact that he was taken hostage when trying to help others and now murdered demonstrates that there are no limits to the depravity of these ... terrorists.

"We will do all we can to hunt down these murderers and bring them to justice."

What is this "bring them to justice" crap? Are we going to send the FBI - or the Brits send a few Bobbies - to arrest these guys? Who are they kidding?

This is exactly the wrong way to fight terrorists. Forget about hunting down Jihad John. Just kill as many of the terrorists as possible. And then keep killing them. And then kill some more and don't stop until they're too terririfed to be seen in public.

But that won't happen. ISIS flouts every single rule that governs civilized warfare. It's why they are winning. It's like ISIS is playing football while we're trying to play Tiddlywinks. Which side is going to come out on top?

Germany and Japan did not give up until we had levelled their cities and killed hundreds of thousands of their people. And we're expecting to defeat ISIS by playing by the rules of civilized warfare? Because we won't be willing to match brutality with brutality - a head for a head - it is likely that we will eventually give up and go home.

That may satisfy the humanitarians out there. But it will leave the beheaders free to do as they please to whomever they wish.