On a dark night at the tail end of last winter, just a month after the inauguration of the new American president, an evening when only a sickle moon hung in the Levantine sky, two Israeli Sikorsky CH-53 helicopters flew low across Jordan and then, staying under the radar, veered north toward the twisting ribbon of shadows that was the Euphrates River. On board, waiting with a professional stillness as they headed into the hostile heart of Syria, were Sayeret Matkal commandos, the Jewish state’s elite counterterrorism force, along with members of the technological unit of the Mossad, its foreign-espionage agency. Their target: an ISIS cell that was racing to get a deadly new weapon thought to have been devised by Ibrahim al-Asiri, the Saudi national who was al-Qaeda’s master bombmaker in Yemen. It was a covert mission whose details were reconstructed for Vanity Fair by two experts on Israeli intelligence operations. It would lead to the unnerving discovery that ISIS terrorists were working on transforming laptop computers into bombs that could pass undetected through airport security. U.S. Homeland Security officials—quickly followed by British authorities—banned passengers traveling from an accusatory list of Muslim-majority countries from carrying laptops and other portable electronic devices larger than a cell phone on arriving planes. It would not be until four tense months later, as foreign airports began to comply with new, stringent American security directives, that the ban would be lifted on an airport-by-airport basis. In the secretive corridors of the American espionage community, the Israeli mission was praised by knowledgeable officials as a casebook example of a valued ally’s hard-won field intelligence being put to good, arguably even lifesaving, use. Yet this triumph would be overshadowed by an astonishing conversation in the Oval Office in May, when an intemperate President Trump revealed details about the classified mission to Russia’s foreign minister, Sergey V. Lavrov, and Sergey I. Kislyak, then Russia’s ambassador to the U.S. Along with the tempest of far-reaching geopolitical consequences that raged as a result of the president’s disclosure, fresh blood was spilled in his long-running combative relationship with the nation’s clandestine services. Israel—as well as America’s other allies—would rethink its willingness to share raw intelligence, and pretty much the entire Free World was left shaking its collective head in bewilderment as it wondered, not for the first time, what was going on with Trump and Russia. (In fact, Trump’s disturbing choice to hand over highly sensitive intelligence to the Russians is now a focus of special counsel Robert Mueller’s investigation into Trump’s relationship with Russia, both before and after the election.) In the hand-wringing aftermath, the entire event became, as is so often the case with spy stories, a tale about trust and betrayal. And yet, the Israelis cannot say they weren’t warned.

In the American-Israeli intelligence relationship, it is customary for the Mossad station chief and his operatives working under diplomatic cover out of the embassy in Washington to go to the C.I.A.’s Langley, Virginia, headquarters when a meeting is scheduled. This deferential protocol is based on a realistic appraisal of the situation: America is a superpower, and Israel, as one of the country’s senior intelligence officials recently conceded with self-effacing candor, is “a speck of dust in the wind.” Nevertheless, over the years the Israeli dust has been sprinkled with flecks of pure intel gold. As Israeli journalist Ronen Bergman has pointed out, it was back in 1956, when the Cold War was running hot, that Israeli diplomats in Warsaw managed to get their hands on the text of Soviet premier Nikita Khrushchev’s top-secret speech to the Twentieth Party Congress in Moscow. Khrushchev’s startling words were a scathing indictment of Stalin’s three dec­ades of oppressive rule, and signalled a huge shift in Soviet dogma—just the sort of invaluable intelligence the C.I.A. was eager to get its hands on. Recognizing the value of what they had, the Israelis quickly delivered the text to U.S. officials. And with this unexpected gift, a mutually beneficial relationship between the resourceful Jewish spies and the American intelligence Leviathan began to take root. Over the ensuing decades it has expanded into a true working partnership. The two countries have gone as far as to institutionalize their joint spying. The purloined documents released to the press by Edward Snowden, for example, revealed that the N.S.A., the American electronic-intelligence agency that eavesdrops on the world, and Unit 8200, its Israeli counterpart, have an agreement to share the holiest of intelligence holies: raw electronic intercepts. And the two countries inventively worked in tandem, during the administration of George W. Bush and continuing with President Obama, on Operation Olympic Games, creating and disseminating the pernicious computer viruses that succeeded in damaging Iran’s uranium-enrichment centrifuges. American and Israeli spooks have even killed together. In 2008, after President George W. Bush signed off on the operation, the C.I.A. cooperated with agents from the Mossad’s Kidon—the Hebrew word for “bayonet,” an appropriate name for a sharp-edged unit that specializes in what Israeli officials euphemistically call “targeted prevention.” The shared target was Imad Mughniyah, the Hezbollah international operations chief, and any further terrorist acts he’d been planning were quite effectively prevented: Mughniyah was blown to pieces, body parts flying across a Damascus parking lot, as he passed an S.U.V. containing a specially-designed C.I.A. bomb. But like any marriage, the cozy—yet inherently unequal—partnership between the American and Israeli intelligence agencies has had its share of stormy weather. In fact, according to Bergman, an irreparable divorce seemed likely in 1985 after it was discovered that Israel was running a very productive agent, Jonathan Pollard, inside U.S. Naval Intelligence. For a difficult period—measured out in years, not months—the American spymasters fumed, and the relationship was more tentative than collaborative. But spies are by instinct and profession a pragmatic breed, and so by the 1990s the existence of shared enemies, as well as shared threats, worked to foster a reconciliation. Besides, each had something the other needed: Israel had agents buried deep in neighboring Arab countries, producing “HUMINT,” as the jargon of the trade refers to information obtained by human assets. While the U.S. possessed the best technological toys its vast wealth could buy; its “SIGINT,” or signals intelligence, could pick up the chatter in most any souk in the Arab world. And so by the time of Trump’s election, despite the snarky, rather personal feud between Prime Minister Netanyahu and President Obama, the two countries’ spies were back playing their old tricks. Together they were taking on a rogues’ gallery of common villains: al-Qaeda, Hamas, Hezbollah, and the Islamic State. “We are the front line,” a high-ranking Israeli military official bragged to me, “in America’s war on terror.” Over recent months, the U.S. intelligence windfall has been particularly bountiful. Israel, according to sources with access to the activities of the Mossad and Unit 8200, has delivered information about Russia’s interaction with the Syrian, Iranian, and Hezbollah forces taking the field in the Syrian civil war. And there is little that gets American military strategists more excited than learning what sort of tactics Russia is employing. It was against this reassuring backdrop of recent success and shared history that a small group of Mossad officers and other intelligence officials took their seats in a Langley conference room on a January morning just weeks before the inauguration of Donald Trump. The meeting, according to Bergman, the author of Rise and Kill First (to be published by Penguin Random House on Jan. 30, 2018), 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 Bergman report. 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. Currents of alarm and anger raced through those present at the meeting, says the Israeli source, but their superiors in Israel remained unconvinced—no supporting evidence, after all, had been provided—and chose to ignore the prognostication.

The covert mission into the forbidden plains of northern Syria was a “blue and white” undertaking, as Israel, referring to the colors of its flag, calls ops that are carried out solely by agents of the Jewish state. Yet—and this is an ironclad operational rule—getting agents in and then swiftly out of enemy territory under the protection of the nighttime darkness can be accomplished only if there is sufficient reconnaissance: the units need to know exactly where to strike, what to expect, what might be out there waiting for them in the shadows. For the mission last winter that targeted a cell of terrorist bombers, according to ABC News, citing American officials, the dangerous groundwork was done by an Israeli spy planted deep inside ISIS territory. Whether he was a double agent Israel had either turned or infiltrated into the ISIS cell, or whether he was simply a local who’d happened to stumble upon some provocative information he realized he could sell—those details remain locked in the secret history of the mission. What is apparent after interviews with intelligence sources both in Israel and the U.S. is that on the night of the infiltration the helicopters carrying the blue-and-white units came down several miles from their target. Two jeeps bearing Syrian Army markings were unloaded, the men hopped in, and, hearts racing, they drove as if it had been the most natural of patrols into the pre-dawn stillness of an enemy city. “A shadow unit of ghosts” is what the generals of Aman, Israel’s military-intelligence organization, envisioned when they set up Sayeret Matkal. And on this night the soldiers fanned out like ghosts in the shadows, armed and on protective alert, as the Mossad tech agents did their work. Again, the operational details are sparse, and even contradictory. One source said the actual room where the ISIS cell would meet was spiked, a tiny marvel of a microphone placed where it would never be noticed. Another maintained that an adjacent telephone junction box had been ingeniously manipulated so that every word spoken in a specific location would be overheard. The sources agree, however, that the teams got in and out that night, and, even before the returning choppers landed back in Israel, it was confirmed to the jubilant operatives that the audio intercept was already up and running. Now the waiting began. From an antenna-strewn base near the summit of the Golan Heights, on Israel’s border with Syria, listeners from Unit 8200 monitored the transmissions traveling across the ether from the target in northern Syria. Surveillance is a game played long, but after several wasted days 8200’s analysts were starting to suspect that their colleagues had been misinformed, possibly deliberately, by the source in the field. They were beginning to fear that all the risk had been taken without any genuine prospect of reward. Then what they’d been waiting for was suddenly coming in loud and clear, according to Israeli sources familiar with the operation: it was, as a sullen spy official described it, “a primer in constructing a terror weapon.” With an unemotional precision, an ISIS soldier detailed how to turn a laptop computer into a terror weapon that could pass through airport security and be carried on board a passenger plane. ISIS had obtained a new way to cause airliners to explode suddenly, free-falling from the sky in flames. When the news of this frightening ISIS lecture arrived at Mossad’s headquarters outside Tel Aviv, officials quickly decided to share the field intelligence with their American counterparts. The urgency of the highly classified information trumped any security misgivings. Still, as one senior Israeli military official suggested, the Israeli decision was also egged on by a professional vanity: they wanted their partners in Washington to marvel at the sort of impossible missions they could pull off. They did. It was a much-admired, as well as appreciated, gift—and it scared the living hell out of the American spymasters who received it.

On the cloudy spring morning of May 10, just an uneasy day after the president’s sudden firing of F.B.I. director James B. Comey, who had been leading the probe into possible collusion between the Trump campaign and Russian operatives, a beaming President Trump huddled in the Oval Office with Sergey Lavrov and Sergey Kislyak. And, no less improbably, Trump seemed not to notice, or feel restrained by, the unfortunate timing of his conversation with Russian officials who were quite possibly co-conspirators in a plot to undermine the U.S. electoral process. Instead, full of a chummy candor, the president turned to his Russian guests and blithely acknowledged the elephant lurking in the room. “I just fired the head of the F.B.I.,” he said, according to a record of the meeting shared with The New York Times. “He was crazy, a real nut job.” With the sort of gruff pragmatism a Mafia don would use to justify the necessity of a hit, he further explained, “I faced great pressure because of Russia. That’s taken off.” Yet that was only the morning’s perplexing prelude. What had been an unseemly conversation between the president and two high-ranking Russian officials soon turned into something more dangerous. “I get great intel,” the president suddenly boasted, as prideful as if he were bragging about the amenities at one of his company’s hotels. “I have people brief me on great intel every day.” He quickly went on to share with representatives of a foreign adversary not only the broad outlines of the plot to turn laptop computers into airborne bombs but also at least one highly classified operational detail—the sort of sensitive, locked-in-the-vault intel that was not shared with even Congress or friendly governments. The president did not name the U.S. partner who had spearheaded the operation. (Journalists, immediately all over the astonishing story, would soon out Israel). But, more problematic, President Trump cavalierly identified the specific city in ISIS-held territory where the threat had been detected. As for the two Russians, there’s no record of their response. Their silence would be understandable: why interrupt the flow of information? But in their minds, no doubt they were already drafting the cable they’d send to the Kremlin detailing their great espionage coup.

So why? Why did a president who has time after volatile time railed against leakers, who has attacked Hillary Clinton for playing fast and loose with classified information, cozy up to a couple of Russian bigwigs in the Oval Office and breezily offer government secrets? Any answer is at best conjecture. Yet in the search for an important truth, consider these hypotheses, each of which has its own supporters among past and current members of the U.S. intelligence community. The first is a bit of armchair psychology. In Trump’s irrepressible way of living in the world, wealth is real only if other people believe you’re rich. If you don’t flaunt it, then you might as well not have it. So there is the new president, shaky as any bounder might be in the complicated world of international politics, sitting down to a head-to-head with a pair of experienced Russians. How can he impress them? Get them to appreciate that he’s not some lightweight, but rather a genuine player on the world stage? There’s also the school of thought that the episode is another unfortunate example of Trump’s impressionable worldview being routinely shaped by the last thing he’s heard, be it that morning’s broadcast of Fox & Friends or an intelligence briefing in the Oval Office. As advocates of this theory point out, the president was likely told that one of the issues still on his guests’ minds would be the terrorist explosion back in October 2015 that brought down a Russian passenger plane flying above Egypt’s Sinai Peninsula, killing all 224 people on board. With that seed planted in the president’s undisciplined mind, it’s a short leap for him to be off and running to the Russians about what he knew about an ISIS scheme to target passenger aircraft. Yet there is also a more sinister way to connect all the dots. There are some petulant voices in official Washington who insist that the president’s treachery was deliberate, part of his longtime collaboration with the Russians. It is a true believer’s orthodoxy, one which predicts that the meeting will wind up being one more damning count in an indictment that Robert Mueller, the special counsel, will ultimately nail to the White House door. But, for now, to bolster their still very circumstantial case, they point to a curiosity surrounding the meeting in the Oval Office—U.S. journalists were kept out. And, no less an oddity, the Russian press was allowed in. It was the photographer from TASS, the state-run Russian news agency, who snapped the only shots that documented the occasion for posterity. Or, for that matter, for the grand jury.