There is no need for the government of Israel to answer the question of whether Mossad agents were responsible for assassinating Hamas operative Mahmoud al-Mabhouh in Dubai; the smiles on the ministers' faces as they left the weekly cabinet meeting on Sunday said it all. And a sense of satisfaction is not unreasonable. The intelligence was reliable and accurate, and the implementation went off without a hitch. Even though Mabhouh knew Israeli intelligence had him in its sights and therefore took stringent precautions, the executors managed to get him.

Mabhouh was a very experienced operative who had in recent years served as Hamas' liaison officer to Iran, responsible for coordinating arms shipments from the Islamic Republic to the Gaza Strip. He labored over plans to equip his organization with "strategic" weapons - long-range missiles and anti-aircraft missiles. His death will disrupt Hamas' activity in this field for some time, as every such assassination forces senior members of the affected organization to concentrate on ensuring their personal security, thus diverting them from their principal occupation: planning operations against Israel.

Since the 1960s, Israel has liquidated hundreds of terrorists who were members of the Palestine Liberation Organization, Hamas, Islamic Jihad and Hezbollah. And that is without even mentioning its policy of wholesale liquidations during the second intifada, which began in 2000. These were euphemistically termed "targeted killings," even though they often entailed the deaths of innocent civilians.

For decades, Israeli intelligence has been entangled in a complex coil from which it is having trouble escaping. The role of intelligence agencies is to gather information about the enemy's capabilities and intentions, to warn of the danger of war and to enable politicians to make better decisions based on the intelligence they procure. The Mossad is not Murder Inc., like the Mafia; its goal is not to take vengeance on its enemies. "Special operations," like the assassination in Dubai - if this indeed was a Mossad operation - have always accounted for a relatively small proportion of its overall activity. Nevertheless, these are the operations that give the organization its halo, its shining image. This is ultimately liable to blind its own ranks, cause them to become intoxicated by their own success, and thus divert their attention from their primary mission.

David Kimche, a former senior Mossad official, once described a heated argument within the organization following the murder of 11 Israeli athletes at the 1972 Munich Olympic Games. With the consent of then-prime minister Golda Meir, Mossad chief Zvi Zamir ordered a campaign of assassinations of PLO operatives. A few years ago, Zamir claimed that the goal had not been to take revenge, but to damage the PLO's infrastructure in Europe and thus foil its plans for additional terror attacks. Yet the suspicion always creeps in that the desire for revenge also has an influence on operations of this type. And according to Kimche, some Mossad employees thought at the time that an intelligence agency should not be engaging in liquidations.

Over the years, on the basis of past precedents, the intelligence community tried to untangle the knot and develop a sort of "combat doctrine" for this type of operation. This doctrine holds that only assassinating the leaders of a terrorist group can have a strategic impact, as this is thought to deal a severe blow to the organization. Intelligence professionals cite the 1979 killing of Zuheir Mohsen, head of the pro-Syrian as-Sa'iqa faction, as an example of such an assassination: After his death, the organization fell apart.

But the assassinations - according to foreign reports - of the PLO's Abu Jihad (1988), Islamic Jihad leader Fathi Shikaki (1995) and Hezbollah's Imad Mughniyeh (2008), though they dealt severe blows to their respective organizations, did not cause them to collapse. And this is all the more true when the person assassinated is a mid-level operative like Mabhouh. Every terrorist, no matter how senior, is soon replaced, sometimes by someone even better or more professional.

It sometimes seems as if Israel is caught in a trap it cannot escape. It cannot simply sit with its hands folded; it must take action against the terrorist groups - respond to their attacks, harass them, hurt them. Yet such operations, and especially assassinations, have no long-term impact on the balance of power. Getting rid of Mabhouh will have only a marginal impact on the battle between Hamas and Israel. He, too, will be suitably replaced. Indeed, Mabhouh himself acquired his last job, which he performed with great success, following the 2006 assassination of his predecessor, Iz a-Din al-Sheikh Khalil, in Damascus. Mabhouh's assassination will thus have only tactical significance.