President Donald Trump’s firing of FBI Director James Comey, the man leading the investigation of the Trump campaign’s ties to Russia, would have been bad enough. The revelation that the president pressured Comey to back off investigating former National Security Adviser Michael T. Flynn would have been bad enough.

But for the president to meet with senior Russian officials in the Oval Office and divulge to them top-secret intelligence — intelligence that most say originated with Israel, no less — is to cross a red line no president should ever cross.

The intelligence the president let slip out had to do with the fight against ISIS. Israeli officials told Reuters that it is possible this intelligence stemmed from an Israeli asset embedded with ISIS. If true, Trump’s loose lips surely put that asset — that human being — in grave danger.

In one moment of bluster, Trump betrayed our ally and provided aid and comfort to our adversary, Russia, a nation chummy with some of the world’s worst actors, including Israel’s sworn enemy Iran. And his timing was stupefying — shortly before his first official trip to Israel.

A pall has now been cast over that visit. As noted in one press report, Israel is “boiling mad.” Former Mossad chief Shabtai Shavit told the Times of Israel that if he were head of Israeli intelligence today he would do “everything I could” not to pass on intel to the CIA, calling Trump a “bull in a china shop.”

Another former Mossad chief, Danny Yatom, said Israel should penalize the United States for Trump’s action so that “we don’t put Trump in a position where he is again tempted.”

Israel is not our only ally undergoing an agonizing reappraisal of its intelligence sharing arrangements with us in the wake of Trump’s betrayal. European leaders have said they, too, will think twice before sharing what they know, with one German parliament member calling the American president potentially “a security risk for the entire Western world.”

What hath Trump wrought? Only a mushrooming disaster when it comes to keeping the world safe. No wonder the “i” word, impeachment, is being bandied about.

Certainly more needs to be learned. That is why we join the increasingly loud chorus demanding the appointment of a special prosecutor to look into Trump’s Russia ties and his reported attempt to obstruct justice.

He said he knew more about fighting ISIS than the generals. He blasted Hillary Clinton for being slipshod with classified information. After the stunning revelations of the past 10 days, it becomes ever clearer that Donald Trump is leading this country down a very dangerous path.