In a debate that took place in the 1990s between two schools of airpower strategists, different views were presented regarding the effectiveness of decapitation as a war-winning strategy. Although it focused on high-intensity conflict (HIC) rather than low-intensity conflict (LIC) situations in general and counter-terrorism in particular, and on physical destruction rather than morale, it nevertheless reflects a basic dilemma between political and military centers of gravity.

According to John Warden, the most effective way of incapacitating the enemy and causing its defeat is to target its decision makers. Warden presents a comprehensive, five-ring model that is reflective of a system of centers of gravity, ranging from the nation’s leadership (the innermost target), key production, infrastructure, and a population’s support for its government to fielded military forces (the outermost ring), in that order of priority and importance. He considers decapitation of leadership the most effective way of imposing one’s will on the enemy, although he recommends simultaneous strikes on each ring’s center of gravity.[33] Robert Pape, on the other hand, is skeptical about the chances of eliminating enemy leadership,[34] as "individual leaders are hard to kill, governments are harder to overthrow, and even if the target government can be overthrown, the coercer can rarely guarantee that its replacement will be more forthcoming."[35] He warns that in cases where leadership strikes or strategic bombings fail, the consequences could lash back and even be catastrophic, as happened after NATO’s air strikes near Belgrade in March 1999, which were followed by the killing and ethnic cleansing of thousands of Albanians.[36] Instead Pape recommends conventional combat against fielded forces at the operational level. He doubts airpower’s effectiveness in terror and guerrilla situations for two main reasons: first, it is difficult to discriminate between guerrillas or terrorists and the population.[37] Second, although decapitation of suicide terrorists can disrupt their organization’s operations temporarily, it rarely yields long-term gains.[38] TK usually aims not only at a terror organization’s leadership, in accordance with Warden’s preference, but also at terror operatives who could be considered military targets. Pape’s theory does seem to apply to terror or guerrilla situations, where large fielded forces are not employed, although he may be right regarding the long-term outcomes.

Asaf and Noam Zussman’s approach integrates Warden’s and Pape’s ideas. On the one hand, they recommend the targeting of senior leaders with specialized knowledge and skills, based on their belief that it will have the strongest effect on the terrorists’ capabilities. At the same time, however, they distinguish between military and political leaders, preferring the targeting of the former. Underlying their preference is the claim that the targeting of political and spiritual leaders will not significantly decrease the capability of the terrorist organization, and will only increase the motivation to carry out terrorist attacks. Targeting low-rank terrorists, in their view, is not likely to disrupt seriously the operation of the organization, whereas the targeting of senior military leaders will generate little increase in the motivation of the organization to carry out attacks and will evoke less rage and fewer calls for retaliation than the killing of political leaders. It also has the potential to severely disrupt the organization’s operations, as military leaders are involved in planning operations and recruiting, training, arming, and dispatching terrorists.[39] As much as this thesis seems logical, the Israeli case does not support it, as will be shown below.

Due to the elusiveness of terrorists, the process of spotting a new target, assigning a weapon to hit it, and finally hitting it, must be as short as possible. Advanced command and control systems, as well as improved intelligence, surveillance, and reconnaissance (ISR) capabilities could shorten this process considerably – from days to minutes.[40] Not only does this require technological capability; it also makes it necessary to implement a high degree of inter-service jointness, which means that bureaucratic and organizational affiliations and loyalties must be overcome.

One of the most famous examples of failure to close the loop is probably the missed opportunity to kill Taliban leader Mullah Omar Mohammed in Afghanistan in October 2001, when a CIA-controlled unmanned Predator reconnaissance aircraft identified a group of cars and trucks fleeing the capital as a convoy carrying the Taliban leader. As the CIA did not have the authority to "push the button," the decision had to be made by officers on duty at CENTCOM (US Central Command) headquarters. As a legal officer in CENTCOM did not like the idea of possible collateral damage, it was impossible to strike immediately. The convoy was not targeted and Omar survived.[41]

In the period September 2000-April 2004, Israel carried out 159 TK attempts, dozens of attempts each year, with the highest rate – 56 attempts (35 percent) – in 2002, after 40 attempts (25 percent) in 2001 and 44 attempts (28 percent) in 2003. The decline can be explained by the fact that in mid-2002 the IDF regained control of the West Bank and could afford to arrest rather than kill in this area. Most of the strikes — 69 percent — took place in the West Bank.

TK methods included shooting from close range or by snipers (47 percent), launching missiles from helicopter gunships (34 percent), explosive devices, such as booby-trapped vehicles (14 percent), and other methods (5 percent).

Since in some cases members of more than one organization were targeted simultaneously, division by organizational affiliation is difficult. It is estimated, though that some 50 percent belonged to Hamas, some 31 percent to Fatah, 17 percent to Islamic Jihad, and the rest to other organizations.

Eighty-five percent of the attempts ended up with the targets killed; the rest were injured or saved. These high rates of success were achieved thanks to high-quality intelligence, based on a combination of SIGINT, HUMINT, and a variety of vision devices, such as unmanned aerial vehicles (UAVs), which led the Israelis to their targets. Additionally, increased joint inter-service (ground forces-military intelligence-air force-police-GSS) activity allowed the IDF to overcome the problem of targeting an elusive enemy,[44] after overcoming bureaucratic and organizational affiliations and loyalties.

Jointness also helped shorten the sensor-to-shooter loop. Joint Computerized Command Control Communications and Intelligence (C⁴I) operation centers were established, working for the first time in IDF history as joint operational entities,[45] providing visual monitoring to all command levels, down to the tactical leaders, or helicopter gunships — all being able to see the same evolving battle picture on their computer screens. The GSS provided real time intelligence through its channels, the Israeli Air Force (IAF) extended and verified information through its UAVs and other aerial platforms, IDF’s Field Intelligence supplied updated combat resources from its observation units, and once the intelligence picture had been completed, the field commanders decided on the best way to carry out the mission that was then monitored throughout by the C⁴I command centers, which also debriefed the mission commanders once the mission was terminated.[46]

Seventy-five percent of the attempts were carried out against low level local military leaders or operatives. The rest were senior leaders — either senior military leaders in charge of planning terror operations, and recruiting, training, arming, and dispatching terrorists, like Raad Karmi (September 2001), Atef Abayat (October 2001), Salah Shehadeh (July 2002) (some 17 percent), or senior political-ideological leaders responsible for funding, political and spiritual guidance, and direction of the organization’s strategy, like Ibrahim al-Makadme (August 2003), Ahmed Yassin (March 2004), and Abdel Aziz Rantisi (April 2004) (some 8 percent).[47]

Zussman and Zussman were right in claiming that the emphasis on low rank operatives would be ineffective.[48] The "lawn mower" method applied by the IDF, that is, killing those who assumed senior positions in a local cell each time, did not seriously disrupt the terror organizations’ operation. "Keeping the lawn mowed" permanently required continuous, routine, "automatic pilot"-style, not to say Sisyphean, TK of operatives.[49] In an interview to Haaretz in September 2003, even Deputy Chief of the GSS, Yuval Diskin, who was considered the father of the TK method, expressed his doubts regarding its effectiveness.[50]

When Zussman and Zussman suggested that it would be mostly effective to target Palestinian military rather than political leaders, they believed that targeting senior political leaders would only increase the motivation of their organizations to carry out terrorist attacks due to two factors. First, political leaders were typically far better known to the Palestinian public than military leaders. Second, targeting Palestinian military leaders was considered by both Palestinians and Israelis as part of the "rules of the game," whereas attempts to kill political leaders constituted crossing a "red line."[51]

In September 2001, shortly after the killing of Secretary-General of the Popular Front for the Liberation of Palestine (PFLP), Abu-Ali Mustafa, Chief of Military Intelligence Amos Malka claimed that the targeting of a senior political level was both illegitimate and ineffective in thwarting terror attacks.[52] Former minister Dan Meridor recommended that Israel should limit itself to targeting those directly involved in terror attacks – the suicide bombers and the ones who planned the attacks — and refrain from targeting leaders, not only because international law hardly allowed it but also because of the danger that retaliation would be aimed at Jewish communities abroad, as was the case after the killing of Hezbollah Secretary-General Abbas Mussawi in 1992.[53] Steven David identified great concern on the part of the leaders of the terror organization that they would be eliminated, as well as signs of readiness on their part to modify or cease attacks against Israeli civilians if Israel would suspend its practice of targeted killings.[54] But he too preferred upholding the norm against killing political leaders.[55]

Zussman and Zussman, Malka, and Meridor had it wrong. Targeting military leaders and operatives failed in affecting the stability and morale of the terrorist organizations, in increasing tensions and personal competition among heirs, in thwarting planned terror attacks, and in forcing the organizations to waste time and energy in protecting leaders and finding hiding places for operatives.[56] It rather elevated specific individuals to martyrdom, strengthening their resolve.[57]

New terrorists replaced eliminated ones, proving that it was difficult to effectively destroy a highly motivated, decentralized, and compartmentalized organization. TK of military leaders and operatives also provoked murderous retaliations, with unprecedented numbers of Israeli civilians being killed, which only stimulated further escalation and riots. For example, following the January 2001 killing of Fatah military leaders in Tulkarm Raad Karmi, Tanzim and al-Aqsa Martyrs Brigades launched terrorist attacks that claimed the lives of 57 Israelis. Perpetrated suicide bombing from 2001 to 2003 intensified from 54 cases in 2001 (34 carried out, 20 thwarted) to 167 in 2002 (55, 112, respectively) to 209 in 2003 (25, 184). Only in 2004 did the number drop to 130 (14, 116) (see Table 2).[58] The number of Hamas attacks grew steadily as the intifada progressed, despite Israeli TKs: 19 attacks in 2001, 34 in 2002, 46 in 2003, 202 in 2004, and 179 in 2005 (most of them in the first half of that year, before Hamas agreed to suspend hostilities against Israel temporarily).[59] A study by Edward Kaplan from Yale University on the suicide bombing attacks on Israel during the second intifada found strong statistical evidence that TKs as a counter-terror tactic were associated with an increase in suicide bombing attempts; each additional hit appeared to invite an additional 7.75 attempts.[60]

This should not have come as a surprise. Earlier, in 1996, the killing of Yihya Ayyash ("the engineer") was followed by a wave of suicide bombings that claimed the lives of 59 Israelis and wounded 250. TKs also resulted in informers uncovered, intelligence resources diverted, and international condemnation of Israel.[61]

As for as the killing of political leaders, it is true that the killing of Abu-Ali Mustafa, Secretary-General of the PFLP, in August 2001 accounted for the killing of Israeli Minister of Tourism Rehavam Zeevi as revenge two months later. However, the PFLP was a small organization, and as such Mustafa could not be considered a significant center of gravity as far as the Palestinian struggle against Israel as a whole was concerned. The elimination of Islamic Jihad leader, Fathi Shikaki, in Malta in October 1995 did paralyze the organization for a few years,[62] although it had only a limited effect on Palestinian anti-Israel terror activities because of the relatively small size and limited significance of Islamic Jihad at the time.

However, one cannot disregard the correlation between Hamas’s consent to the unilaterally announced Palestinian hudna (temporary suspension of hostilities) of 29 June 2004 and the killing of its spiritual leader Sheikh Yassin in March 2004 and the killing of the organization’s leaders in the Gaza Strip, Abu Shanab in August 2003 and Abdel Aziz Rantisi in April 2004. Not only were Yassin and Rantisi not replaced by a new chief leader, which both reflected and created a leadership vacuum, but Mahmoud al-Zahar – one of the two remaining top Hamas leaders in the Gaza Strip who had escaped an attempted TK (the other one was Sheikh Isma’il Haniyya) – for the first time expressed the organization’s interest in taking part in the political system following Israel's withdrawal from the Gaza Strip.[63]

Hamas’ leadership feared TK so greatly that when in September 2005 Israeli Defense Minister Shaul Mofaz warned two of its leaders, Mahmoud al-Zahar and Isma’il Haniyya, that should they or any of the other Hamas leaders continue firing Qassam rockets to Israeli territory, "we will send them to place where Rantisi and Yassin are,"[64] Hamas announced its decision to stop firing the rockets. These findings seem to support John Warden’s view on the effectiveness of the decapitation of political leadership.

The new policy of targeting senior political leaders seems to have permeated Israeli thinking. In February 2006, former GSS head Avi Dichter warned that if Israel should find itself obliged to retaliate after a Palestinian terrorist attack, Hamas leader Haniyya could constitute a legitimate target killing even if he becomes prime minister.[65] In mid-2007, it was reported that following the Second Lebanon War a special branch in AMAN (Israeli military intelligence) was established for collecting real-time intelligence from various sources on enemy senior leaders in order to be able to spot them and assign a weapon system to hit them shortly after being identified, if necessary.[66]

Since mid-2002, the terrorists’ successes declined significantly, although this did not mark the end of the intifada. For example, after having claimed the lives of 3.9 Israelis per attack in 2001 and 5.4 in 2002, the death toll claimed by Hamas terrorists per attack dropped to 0.98 in 2003, 0.33 in 2004, and 0.11 in 2005.[67] Israeli TK performance notwithstanding, no causal relationship could be proven between TK and this decline. Other factors were involved in decreasing the terrorist successes, such as Israeli strikes into the territories, particularly Operation Defensive Shield, in 2002, during which the IDF regained control over the West Bank, and the construction of the security fence since 2003.[68]

During Operation Defensive Shield the IDF entered cities, rural areas, and refugee camps in the West Bank, carrying out continuous offensive activity at the tactical level and intensifying TK of terrorist operatives. A sharp decline of over 50 percent in suicide bombings took place in the wake of the operation – from 60 in 2002 to 26 in 2003 and 13 in the period January-September 2005.[69] The number of fatalities declined from 452 in 2002 to 214 in 2003. The number kept declining in 2004, to 97 in the period January-September.[70] In 2003 and 2004, Israel managed to thwart almost 90 percent of the perpetrated terror attacks (88 percent and 89 percent, respectively), as compared to 67 percent in 2002 (see Table 3).[71]

Since late-2003, a buffer zone between Israel and the West Bank has been under construction. Troops deployed along the buffer zone have been controlled by the aforementioned C⁴I centers, which have been monitoring all ground, airborne (UAV), and aerostat surveillance assets. Since the creation of the security fence, the number of terrorist attacks dropped sharply – from 73 in the period September 2000-July 2003 (an average of 26 terrorist attacks per year) to 5 in the period July 2003-August 2004. The number of fatal casualties inflicted by terrorist attacks from the West Bank in the period August 2003-August 2004 dropped, too, by some 84 percent as compared to the period September 2001-July 2002 (see Table 4).[72]

Yaser Arafat’s death in late 2004 and the election of Abu Mazen as his successor changed the atmosphere in the territories toward more moderation. PAHamas dialogue was resumed and resulted in a new hudna. This, however, happened only after the Hamas leadership had been under threat of elimination.[73]