Horrific new atrocity photos flowed from the Middle East Friday. Only this time the victims were Palestinians, not Americans, and the killers were from Hamas, not ISIS.

Angered by Israel’s successful hit on three of its top commanders in an airstrike, Hamas lined 18 “informers” against a wall and publicly gunned them down. This, declared Hamas, was “revolutionary justice,” vowing that more such killings will follow.

Summary executions are nothing new to Hamas, of course. Yet much of the world thinks it’s engaged in legitimate resistance to “Zionist occupation.”

And that’s alarming — because it’s becoming increasingly clear that there’s little difference between groups like ISIS, Hamas, Boko Haram, al Qaeda and the Taliban.

The savage videotaped beheading of US journalist James Foley — and the sick language ISIS used in an e-mail to his family, vowing to continue slaughtering Americans “UNTILL WE QUENCH OUR THIRST FOR YOUR BLOOD” — was not an isolated act.

It’s the normal behavior for the neo-Islamist groups intent on establishing their caliphate and destroying anyone who stands in their way.

As Israeli Prime Minister Benjamin Netanyahu warned this week: “Hamas is ISIS, ISIS is Hamas. You saw the gruesome beheading of James Foley. We see the gruesome murder and execution of three teenagers, which Hamas has just admitted that they did. These are both branches of the same poisonous tree.”

If such groups, as Defense Chuck Hagel warned, are like nothing the world has seen before, it will take a similar response to destroy them. Israel, at least, recognizes this.