During the heat of this past summer in Dubai, when the beaches were too hot for sunbathing and the city hummed with air conditioners working overtime, Mahmoud al-Mabhouh, a senior member of Hamas, the militant Islamic group that controls Gaza, quietly checked into a hospital for unspecified “treatment.” In fact, he was recovering from an attempt by the Mossad, Israel’s legendary spy agency, to poison his food during an earlier visit to Lebanon, an Israeli source said.Though he apparently did not realize it, Mabhouh was being closely watched. Members of what is now estimated to have been an 18-person Mossad assassination squad were tracking his every move, from his home in Damascus to his hospital room in Dubai. Members of the team infiltrated the hospital and were prepared to assassinate him but the attempt was called off due to what was described as a “glitch.”Last November, Mabhouh was in Dubai again, en route to yet another prospective purchase of weapons for Hamas. Once again, he was not alone. Throughout his brief stay in Dubai and when he boarded his plane for China, a member of a Mossad assassination squad accompanied the target, reporting on where he went in China, whom he met and contacted, and where he stayed, dined, and slept.Israel has remained silent about the murder, in keeping with its longstanding policy of not commenting on such operations, but an Israeli source suggests that the near-miss in the Dubai hospital and the trip to China were only two incidents in an intense, protracted surveillance effort that preceded the Mossad’s meticulously planned assassination on January 19th of a man who had been on Israel’s “most wanted” list for almost two decades. Mahmoud al-Mabhouh had been on the run ever since he helped to kidnap and later kill two Israeli soldiers on leave in 1989.But what put al-Mabhouh so prominently in Israel’s sights were not his past deeds, but his leading role in the supply of weapons from Iran. As an Israeli reporter put it to me, al-Mabhouh’s death was a “two-fer”—a man who from Israel’s standpoint deserved killing not only for having murdered Israelis in the past, but also because he was buying weapons from Iran that would be used to kill Israelis in the future.Al-Mabhouh’s assassination in Dubai is the latest in a series of Israeli killings of individuals from Hamas or Hezbollah who traffic in arms and intelligence from the Islamic Republic. The assassination campaign, which would have been approved at the highest levels of government, seems to be part of a broader strategy to disrupt Iran’s nuclear program and confound Teheran’s efforts to surround Israel with militant enemies on its northern border in Lebanon and to the south in Gaza.In December, two Hamas officials were killed in a mysterious blast in Beirut. Last year, Sudan, which is allied with Iran and openly hosts Hamas, accused Israel of attacking a convoy in a remote mountainous region in northeastern Sudan. The Associated Press and other news agencies reported that strikes were aimed at convoys that were allegedly filled with weapons bound for Hamas. The Mossad has also been linked to the disappearance of Iranian nuclear officials, though it is unclear whether they were killed or have defected to the West.Most famously, the Mossad has been accused of having assassinated Imad Mughniyeh, the senior Hezbollah official responsible for the bombing of the U.S. Marine compound in Beirut in 1983, soon after he attended a gathering at the home of the Iranian cultural attaché in Damascus, not far from the headquarters of Syrian military intelligence. Mughniyeh, who was said to be hyper-attentive to his personal security, was decapitated in 2008 when the headrest of his car seat exploded.Six months later, Mossad, in cooperation with special forces, struck again at the heart of the Syrian establishment. According to Uzi Mahnaimi, writing in London’s Sunday Times this weekend, General Mohammed Suleiman, Syria’s liaison to North Korea’s nuclear program, was shot and killed by a sniper firing from a yacht sailing by as he was relaxing in the back garden of his villa on the Mediterranean shore.Yedioth Ahronoth, the Israeli daily, was first to report that members of the assassination team that killed Mabhouh on January 19th had made at least two prior visits to Dubai before the trip last month. Over the weekend, Emirati officials confirmed that 11 of the assassination squad members had used cloned foreign passports to visit Dubai at least twice before the January visit.Also over the weekend, Emirati and Hamas officials, both apparently eager to blame the victim rather than themselves for failing to prevent the murder, criticized Mabhouh for having been lax about his own security. In Gaza, Salah Bardawil, a Hamas official, complained to reporters that Mabhouh had broken Hamas security rules by calling his relatives and telling them he was heading to Dubai. Moreover, he said, Mabhouh should not have been booking his hotel room over the Internet. Piling on, Lt. Gen. Dhahi Khalfan Tamim, Dubai’s loquacious police chief, scolded both Mabhouh and Hamas for having failed to take “basic security precautions” to protect so important an official. “If he had at least one person with him, [the suspects] would not have been able to kill him,” Khalfan Tamim told Gulf News, a Dubai-based English language paper. “It was clear that he had that feeling that he was anonymous and he was not careful enough,” the police chief charged in an apparent attempt to shift blame for the murder from his emirate to Mabhouh and his organization.When the news first broke, senior Israeli officials neither confirmed nor denied an assertion by Dubai’s Lt. Gen. Khalfan Tamim that he was “99 percent certain” that Israel had dispatched a professional hit team of at least “seven or more people holding passports from different European countries” to kill Mabhouh in Dubai. Over the weekend, Khalfan Tamim elaborated, saying that several of the assassination team members had used their passports in Dubai at least twice before. About three months ago, he said, confirming the Israeli newspaper account, agents using stolen identities had followed Mabhouh from Dubai to China. About two months ago, he added, they had followed him on another visit to Dubai. It was unclear whether this was the trip Mabhouh had made for his medical treatment, which an Israeli source said took place last summer.On Friday, Yedioth Ahronoth disclosed that the team had tracked its prey to Dubai at least twice for what Smadar Perry, the well-connected Israeli journalist, called a “training mission,” and in an earlier, interrupted attempt to kill him. On that second visit, only a “technical” glitch in the mission, the precise nature of which she did not disclose, enabled Mahbouh to escape death.The prior visits to Dubai and the physical positioning of the team members strongly suggest that the Mossad was well aware of the CCTV cameras that Dubai has installed not only at this and other luxury hotels frequented by foreigners, but at airports, shopping malls, and throughout public spaces of the city known for intelligence intrigue and as a commercial entrepot for businessmen of all nationalities, including Israel. What apparently surprised the Mossad was the speed with which the Dubai police traced the movements of the Israeli agents in Dubai. The Emirati police have widely circulated a 30-minute video that outlines the Mossad plot and players as its officials understand it from the moment the agents entered the country until their departure a day later.Watching the video, it seems clear that at least one female member of the hit team, a woman identified by the cloned passport she carried as Gail Folliard, an ostensible Irish citizen, knew she was being taped by the hotel’s security cameras. While photographed in several different guises, she was readily identifiable. At one point, in fact, she seems to be smiling coyly at the camera. But a second female team member was captured only briefly on video and remains unidentified due to her fleeting appearance in oversized sunglasses, broad-brimmed hat, and loose-fitting clothes.Details are still emerging about precisely what happened in Mabhouh’s hotel room at the Al Bustan Rotana Hotel, where his body was discovered by the hotel’s staff a day after the murder. Although it is still unclear how the Israeli agents gained entry to his room and how precisely they killed him—contradictory reports suggest either electrocution or smothering—Mabhouh had taken some precautions to hide his movements since he had referred in an interview with Al Jazeera several months earlier to at least three Israeli attempts to eliminate him. Mabhouh had checked into the hotel using an alias and was said to have propped a heavy arm chair up against his hotel room door before retiring for the night. He had also requested a room without a balcony or external mode of entry.It has been widely reported that the agents left a “Do Not Disturb” sign on Mabhouh’s door, a gesture intended to ensure that the body would not be discovered for several hours and to give themselves sufficient time for a clean getaway. In addition, they managed to latch the door to Mahbouh’s room from the inside. How this feat was performed is also unclear. One Israeli familiar with intelligence operations suggested that a woman agent’s tiny hand might have reached into the small gap between the door and its frame and fastened the chain after she had left the room. Perhaps the hand belongs to the still mysterious agent whom the CCTV cameras have failed to identify, by either her real name or her alias.While Israeli reporters have continued their breathless reporting on the operation under the government’s tight censorship rules, facts and myths about the operation that has fascinated the world, infuriated Hamas, and been quietly condoned by many Arab states, have continued leaking out. The British government, for instance, has adamantly denied that it was tipped off in advance of the mission, or that it was aware that the Mossad had altered photos on genuine passports issued to British-Israelis for the Mossad agents to use. Given Mossad’s secretive modus operandi, Whitehall’s denials seem credible. It is unlikely that the spy agency would have alerted anyone, let alone a country that lambasted Israel two decades ago for having used stolen British passports in Mossad missions, to an operation that the spy agency clearly hoped might leave no fingerprints.The same skepticism must apply to press reports that the Mossad was working with the Palestinian Authority to kill Mahbouh. Such reports fail what one Israeli source called the “smell test.” Yes, two Palestinians from Gaza—Ahmad Hasnin and Anwar Shekhaiber, both of whom had apparently worked for the Palestinian Authority in Ramallah—were arrested and quickly extradited to Dubai soon after the murder and their flight to the Jordanian capital, Amman. And yes, the two had lived in Gaza until Hamas seized control there in 2007 and expelled the P.A. The Israeli newspaper Haaretz reported over the weekend that Hasnin and Shekhaiber had moved to Dubai from Gaza and worked for a real estate company owned by a senior official of Fatah, the main P.A. faction headed by Palestinian President Mahmoud Abbas, Hamas’s bitter rival and foe.Still, it is improbable that Mossad would have involved the P.A. in such a politically sensitive, potentially explosive operation. A more plausible explanation is that the two Palestinians, only one of whom was photographed talking to the putative head of the Mossad mission, were freelancing, that is, picking up some quick cash by providing logistical support for a member of the Israeli team. A source close to Jordanian intelligence suggested to me that “there are three possibilities here”: first, that the “Palestinians were affiliated with the P.A. and authorized to cooperate,” which is possible but not likely; second, that “they were freelancing for pay, which is most likely”; or third, that they were pawns in an internal struggle within Hamas, “which is preposterous—which doesn’t mean that it can’t be true.”The swift extradition of the two Palestinians is easier to understand. Jordan and Dubai are close allies and politically like-minded. The rulers of the two countries are also linked by marriage. The second wife of Sheihk Mohammed bin Rashid al Maktoum, Dubai’s ruler and the United Arab Emirates’ prime minister and vice president, is Princess Haya bint Al Hussein, the daughter of the late King Hussein of Jordan and a half-sister of Jordan’s current ruler, King Abdullah II.Moreover, Jordan has taken a dim view of operations by Mossad on its own territory ever since 1997, when Mossad agents tried and failed to kill Hamas leader Khaled Mashal during a visit to Jordan. On that botched mission, an Israeli Mossad agent blew poison into Mashal’s ear. But the two agents were caught and a furious King Hussein demanded that an antidote be handed over in time to save Mashal, who now leads Hamas’ more radical political wing in Damascus. The failed operation severely strained relations between Israel and Jordan, which remains one of the former’s key regional allies.As for the rest of the Arab states, their silence about the alleged Mossad operation has been deafening. Egypt, Saudi Arabia, and even Syria have said little about the murder, perhaps preferring Israel’s policy of targeted assassinations to its more aggressive expressions of displeasure with programs or actions that endanger its citizens—including Operation Orchard, the 2007 military strike that destroyed Syria’s covert nuclear reactor, and its incursions into Lebanon and Gaza.Meanwhile, countries whose passports were used as cover for the Mossad agents have continued to feign outrage and go through the motions of protest. Ron Prosor, Israel’s ambassador to London, for instance, was summoned to the Foreign Office for a dressing down. Dubai’s police chief Khalfan Tamim is still calling upon Interpol to issue a “red notice” for the arrest of Mossad chief Meir Dagan, the 65-year-old former military officer who emigrated to Israel from Novosibirsk, Siberia.Appointed director of the state spy agency by former Prime Minister Ariel Sharon, Dagan has returned to the lethal covert murders for which the Mossad was once known. Such operations had fallen into disrepute, but they have been revived under Dagan’s stewardship, with Prime Minister Bibi Netanyahu’s blessing. The prime minister, who meets with the Mossad chief at least once a week to review Mossad operations, would have had to approve an operation of this nature, as the Sunday Times reported this weekend. In response to Dubai’s call for the arrest and extradition of Dagan, an unnamed spokesman in Bibi’s office was quoted in the Israeli press as saying that the prime minister retained “full confidence” in Meir Dagan.Judith Miller, Tablet Magazine’s theater critic, is the author of the memoir The Story: A Reporter's Journey.