The Iranian-made drone launched by Hezbollah in southern Lebanon, which penetrated Israeli airspace last Saturday, served as a reminder of the complicated balance of deterrent power between the sides. That Hezbollah, backed by Iran, looms as the most sophisticated antagonist vis-a-vis Israel in the region is not in dispute. Since the last direct clash between the two sides, during the Second Lebanon War in the summer of 2006, both have regrouped and made preparations for any future extended conflict.

The defense establishment continues to keep the findings of its investigation into the drone incident under wraps. Apparently, the unmanned aircraft was not a "suicide" weapon, akin to the three Iranian Ababil drones launched by the Shi'ite organization at Israel during the war six years ago. This drone's purposes were different: to photograph targets in Israel; review Israel's aerial-defense system; and also to reinforce Hezbollah's deterrent credibility as much as possible.

In his speeches, Hezbollah leader Sheikh Hassan Nasrallah frequently alludes to the use of precise rocketry and to his organization's ability to strike Israel's civilian infrastructure, as well as his (rather less plausible ) plan to conquer towns and villages in the Galilee. For Nasrallah, the firing of the drone was a logical ploy. It demonstrated Hezbollah's operational capability, and caused a measure of confusion within Israel.

As things stand now, Hezbollah is unable to use its heavy weapons - particularly, its precise mid- and long-range rockets. Employing such rockets against Israel would drag the region into a war that the Shi'ite "Party of God" organization would prefer to avoid, for now.

For its part, Israel's security establishment is making an ongoing effort to maintain its deterrent edge with regard to Hezbollah (inasmuch as is possible, officials in Jerusalem clearly prefer to play the so-called deterrence card, rather than resorting to attacks ). Concurrently, the officials are also taking steps in the international arena to gain legitimacy for any future military measures that might need to be taken.

This diplomatic preparation for possible war is necessary: The underlying operating assumption is that the next round of conflict will begin under adverse circumstances, from Israel's standpoint. Hezbollah will exploit tactical advantages; its fighters will use civilian populations in southern Lebanon as shields while they fire missiles and rockets at population centers in Israel. This is the background to periodic Israeli declarations, from the "Dahiya Doctrine" enunciated by then-Israel Defense Forces GOC Northern Commander Gadi Eizenkot in 2008, to recent threats articulated by senior IDF officers about how the contents of the "Goldstone Report [into Operation Cast Lead, in Gaza] will be child's play" compared to what will happen in the next war in Lebanon.

Analyzing the details

The IDF recently allowed Haaretz an unusual glimpse into the ways it is preparing for war, based on a "bank" of possible targets in Lebanon. This was a glimpse, not a comprehensive view, and it derives from conversations with intelligence sources, the army's legal advisers and so on.

The lack of a comprehensive list of viable targets was one of the major errors of the 2006 war. On the war's fourth day, Northern Command had already initiated attacks on all 83 targets compiled via intelligence officials prior to the fighting. "S.," an IDF colonel who until recently headed the Northern Command's artillery division, hints that the number of targets currently listed by the command is in the thousands.

"Priority in our operations will be given to anything used as a base for firing rockets at Israel, at its civilian population and at military targets. Subsequently, we will take care of terror organizations' infrastructures, and then, if the need arises, the Lebanese army, should it intervene in the fighting," S. says.

Mirit, an IDF captain who heads the targets division in the IDF Intelligence Corps research branch, explains that her section receives information from the IDF's various information-collection agencies, from photographic missions and from human sources.

"In the end, you have to put together many disparate pieces of information in order to isolate precise target points, places where the enemy hides capabilities," she says. "This might include a storage arsenal for rockets, or an officers' headquarters. You have to analyze details such as the floor of a building where the HQ compound is located, and the direction from which you would have to fire weapons. Operational success is attained only via a high level of precision during a strike and the minimizing of harm to civilians. Information comes to us in raw form, and it has to be processed. We have to assess the source of the information and its reliability, and collect numerous bits of data in order to decide whether a locale represents a viable target."

Mirit adds that "IDF intelligence is highly oriented today toward the compilation of operational intelligence. I don't finish any day's work without taking part in this operative process - one devoted to establishing new targets. The head of IDF intelligence defines the criteria for isolating targets; but it is the soldiers who process raw data, classify it and zero in on possible targets."

After these intelligence officers confirm that selected locales represent viable, hostile targets, the information is relayed to Northern Command or to the Israel Air Force, which is responsible for converting the intelligence information into concrete plans.

"There shouldn't be any illusions here," says Col. S. "Even when the intelligence work is of high quality, it is extremely difficult to monitor a terror organization that takes pains to break established routines. Intelligence does not have a full picture of what happens with Hezbollah."

After the 2006 war, Hezbollah moved most of its resources from various camps in the field - branded "nature reserves" by the IDF - to relatively crowded village and urban locales in Lebanon. S. says that "95 percent of Hezbollah targets are situated in civilian surroundings, and involve the use of civilians as human shields. These are not military bases - they are headquarters and arsenals, located within buildings that also serve as places of residence for civilians."

Precise strikes

When IDF commanders weigh strike options, they must come up with a balance between the operational value of attacking a particular target as compared to the collateral damage that is liable to result.

IDF ballistics and engineering experts are called on to assess, for example, whether an attack on a weapons storehouse located on the ground floor of a residential building will necessarily cause the structure to collapse. In the event of a war, Israel will (as it has in the past ) issue calls to civilian populations in southern Lebanon, telling them to head north.

"Priority will be given to precise, surgical strikes that cause minimal damage to civilians," S. stresses. He speaks in the somewhat sanitized language used by the army to describe the consequences and dangers posed to civilian populations by military attack plans.

"We are upgrading methods of moving the Lebanese population northward quickly, in order to reduce casualties," he says. "We will also drop leaflets and take control of radio broadcasts. Unfortunately, nevertheless, there will be significant damage to population groups that are not involved in the fighting."

The army will protect routes leading toward Beirut that would be used by residents of the south as they flee northward: "We'll make efforts to ensure that those who move north on these pathways will not be harmed," S. adds.

On the first night of the 2006 war, after IDF reservists were kidnapped, Ehud Olmert's government authorized attacks on the homes of Hezbollah militants where mid-range rockets were stored. The IDF warned that such strikes were liable to lead to the deaths of hundreds of civilians. Yet the government's forum of seven authorized the strikes after receiving a briefing from the attorney general, to the effect that an attack on the homes fell within the parameters of international law ("These are families that go to sleep with domesticated missiles resting in the living room," stated then-Defense Minister Amir Peretz ). The IDF strikes resulted in the destruction of dozens of rockets and rocket launchers; dozens, not hundreds, of people were killed in the attack.

Should there be a future round of fighting, the attorney general and the military advocate general will play newly enlarged roles. This change will be a result of the 2009 Goldstone Report. Maj. Roni Yustman, the Northern Command's military advocate, says her office authorizes all designated targets in advance.

"The intention is that all decisions accord with international law," she says. "When the enemy lies within a civilian center, it creates a real challenge. We operate in accordance with the Geneva Convention rules relating to target discrimination , which hold that a target that is in use for military purposes can be attacked."

A residential building that holds weapons, or that is used as an emergency military headquarters, constitutes a viable military target. The IDF has the responsibility of warning the civilian population before an attack, and of assembling high quality intelligence information to ensure a precise strike. Col. S. explains that a target characterized by certain features during normal times might change in a period of war: "When war unfolds quickly, things happen simultaneously, and facts change on the ground. It's not clear that we will be able to sharpen intelligence information at a time when the home front is under attack."

Col. S. adds that "we have the wherewithal to cause heavy damage to Hezbollah. We are training for [war], and I think that future actions will look better than the war in 2006. It will be a clearer, more resolute, fight."

Tension is rife these days in army intelligence and in the Northern Command, owing to concerns about the implications of instability in Syria, and also to what appears to be unpredictable behavior within Hezbollah's leadership. Nasrallah, one top IDF Northern Command officer speculates, "is under pressure because of Syria, and because of Lebanon's domestic situation and demands that he disarm. The massacre of Sunni Muslims in Syria worries Lebanon's Sunni community, and heightens criticism of Hezbollah's partnership with [President Bashar] Assad. For years, there was relative stability in Lebanon due to Hezbollah's prominence. Now the balance of power in Lebanon has changed - Hezbollah's rivals are becoming stronger, and that could actually cause instability. In tandem, there has been some weakening of Israel's deterrence capability vis-a-vis Hezbollah, and this weakening can be seen in the rise of attempted attacks by Hezbollah on targets overseas."

IDF intelligence officers confirm that Nasrallah "is taking more chances than he did in the past. He is planning forms of action against us that would be below the threshold of 'war-causing' provocation." Nonetheless, one top IDF intelligence officer insists, both Israel's and Hezbollah's strategic thinking have some key points in common. At the end of the 2006 conflict in Lebanon, both sides drew the conclusion that it is preferable, for the time being, to avoid a renewed round of war, since its cost would be too high.