When Donald Trump revealed highly sensitive information to Russian Foreign Minister Sergei Lavrov in the Oval Office, he directly endangered the life of an Israeli spy living under deep cover in ISIS territory, ABC News reported last night.

This was the embodiment of Israel’s worst fears. Even before Donald Trump took office, the Israeli intelligence community had quietly expressed concern that information shared with the administration might make its way to Russia and then, through Moscow, to Iran, Israel’s biggest adversary in the region.

The intelligence gathered by this now-compromised spy (or “asset”) was both credible and specific enough that the United States believes ISIS has developed the ability to detonate a device from a laptop inside the main cabin of an airplane — and thus to bring down a US-bound aircraft. Washington is weighing a ban on laptops in carry-on baggage for all flights from Europe; in March, the US and Britain required passengers leaving nearly a dozen Muslim majority nations to check any electronics larger than smartphones.

The kind of highly specific intelligence reportedly provided by Israel is essential to Washington’s ability to prevent a terror attack. But that intelligence was also shared with the US with a major caveat: that the identity of the source remain completely concealed.

“The real risk is not just this source,” Matt Olsen, the former director of the National Counterterrorism Center, told ABC News, “but future sources of information about plots against us.”

In a press briefing yesterday, National Security Adviser H.R. McMaster insisted Trump’s Oval Office disclosures “in no way undermined sources or methods.”

Israel is likely to feel very differently. The country’s security services could pressure Israeli Prime Minister Benjamin Netanyahu to confront Trump about the disclosures when the two men hold a high-profile meeting in Israel next week. Israeli spies themselves may be more cautious about what they share with the US going forward because of the Trump gaffe.

“For them, it is a question of how they acquire information and how they perceive threats against Israel,” Dennis Ross, who has advised several presidents on Middle East issues, told the New York Times. “This will inevitably produce a discussion about the ground rules.”

Israelis neither confirm nor deny. They won’t.

As of this morning, Israeli officials had not confirmed they were the source of Trump’s intelligence information, even though the New York Times also reported that the information originated in Israel.

In a statement emailed to the New York Times yesterday, Israeli Ambassador Ron Dermer merely reiterated his country’s relationship with the United States. “Israel has full confidence in our intelligence-sharing relationship with the United States and looks forward to deepening that relationship in the years ahead under President Trump,” he said.

But that doesn’t mean someone hasn’t been put at risk because of Trump’s loose lips. Brig. Gen. Amnon Sofrin, formerly a senior officer in the Mossad, used a phone call with journalists to express frustration over Trump’s disclosures.

“[A] leader should ask his people about the sensitivity of the information, or consult at least with senior intelligence officers on its uses,” he said.

Sofrin noted that it’s still unclear what exact information was passed from Trump to the Russians, but said such off-the-cuff disclosures “can put sources at risk and damage our activities.”

In a conference call organized by the Brookings Institution, Natan Sachs, the director for Middle East policy at Brookings, dryly stated what most of Washington was thinking all week. “It isn’t good, to put it mildly,” he said, noting, “we don’t know all the details.”

US leaders often pay lip service to the close relationship Washington has with Israel — the phrase “our closest ally in the Middle East” is standard stump speech material. Those aren’t just words: The United States relies heavily on Israel’s extensive and well-sourced spy network, while Israel receives high-tech weaponry from the US, as well as access to important bits of American intelligence.

That could change if Israel feels that the Trump administration can’t be trusted or that its blunders could endanger the lives of Israeli spies and clear the way for sensitive information to wind up in Iranian hands. Jerusalem might decide to limit its intelligence sharing, potentially hampering Washington’s ability to stop terror plots.

With the president a week away from his first trip to Israel, concerns about the strength of that relationship will only get stronger.