From Vanity Fair:
"It was against this reassuring backdrop of recent successes and shared history, an Israeli source told Vanity Fair, that a small group of Mossad officers and other Israeli intelligence officials took their seats in a Langley conference room on a January morning just weeks before the inauguration of Donald Trump. The meeting proceeded uneventfully; updates on a variety of ongoing classified operations were dutifully shared. It was only as the meeting was about to break up that an American spymaster solemnly announced there was one more thing: American intelligence agencies had come to believe that Russian president Vladimir Putin had “leverages of pressure” over Trump, he declared without offering further specifics, according to a report in the Israeli press. Israel, the American officials continued, should “be careful” after January 20—the date of Trump’s inauguration. It was possible that sensitive information shared with the White House and the National Security Council could be leaked to the Russians. A moment later the officials added what many of the Israelis had already deduced: it was reasonable to presume that the Kremlin would share some of what they learned with their ally Iran, Israel’s most dangerous adversary."