A "deeply concerning" leak of U.S. classified documents apparently involving Israel's preparations for a retaliatory attack on Iran was posted on the Telegram Channel of "Middle East Spectator," which is described as pro-Iranian.

CNN authenticated the documents attributed to the U.S. Geospatial Intelligence Agency (NGA) and National Security Agency (NSA). Any intelligence from those agencies is among the most closely guarded secrets of the U.S. government.

“The leak is very concerning. There’s some serious allegations being made there, an investigation underway, and I’ll get a briefing on that in a couple of hours,” Speaker of the House Mike Johnson told CNN’s “State of the Union. “We’re following it closely.”

One of the documents says the Israeli Air Force is preparing for a strike on Iran in retaliation for Iran's missile barrage earlier this month, and conducted “a second large-force employment exercise." The Air Force is “likely to practice air-to-air refueling and combat search and rescue operations with a large number of aircraft,” according to the documents as reported by Politico.

Another document, attributed to the NSA, reports that "Israeli air force exercises involving air-to-surface missiles, also believed to be in preparation for a strike on Iran," according to CNN.

The leak comes at an extremely sensitive moment in US-Israeli relations and is bound to anger the Israelis, who have been preparing to strike Iran in response to Iran’s missile barrage on October 1. One of the documents also suggests something that Israel has always declined to confirm publicly: that the country has nuclear weapons. The document says the US has not seen any indications that Israel plans to use a nuclear weapon against Iran.

“If it is true that Israeli tactical plans to respond to Iran’s attack on October 1 have been leaked, it is a serious breach,” said Mick Mulroy, former deputy assistant secretary of defense for the Middle East and a retired CIA officer.

Mulroy added that “the future coordination between the US and Israel could be challenged as well. Trust is a key component in the relationship, and depending on how this was leaked that trust could be eroded.”

I am not a conspiracy theorist. But with Israel ready to implement plans that were no doubt relayed to Joe Biden during his phone conversation with Israeli Prime Minister Benjamin Netanyahu last week, it's possible that the leak could have American origins. 

Perhaps an American with knowledge of Netanyahu's plans as explained to Biden could have objected to the ferocity of the attack and feared the consequences for the region. The reason I think it was an American is that it's doubtful either of those agencies were hacked and we've seen these leaks by lower-level agency employees before. Jareh Sebastian Dalke, a low level security designer at the NSA, was sentenced to 262 months in April in prison for passing on classified NSA documents to a Russian agent. 

Jack Teixeira, the air National Guardsman who accessed hundreds of classified documents and shared them on gaming chat rooms, was sentenced to 16 years for espionage.  It wouldn't have to be a high-level employee of either agency. 

Times of Israel:

Before that, a senior Israeli official told the Axios news site that the defense establishment was taking the leak very seriously. A US official said that the alleged leak, while extremely concerning, wouldn’t impact plans for an attack against Iran.

The documents, allegedly showing a visual intelligence report by the Department of Defense National Geospatial-Intelligence Agency (NGA), noted observing IAF exercises using air-launched ballistic missiles (ALBMs), air-to-surface ballistic missiles, fighter jets, UAVs, and refueling tankers previously used during Israeli strikes on Houthi sites in Yemen.

According to the documents, the IAF has handled at least 16 Golden Horizon ALBMs and 40 IS02 (Rocks) ALBMs since October 8.

Since there's no indication where the armaments will be targeted, the damage to Israel's plans for the Iran attack isn't serious. The concerning issue is that the security breach is just one more burr under Netanyahu's saddle about the United States and their feckless leader.