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Anatomy of a Successful COIN Operation: OEF-Philippines and The Indirect Approach

Attacking Insurgent Space: Sanctuary Denial and Border Interdiction

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Colonel Joseph D. Celeski, U.S. Army, Retired

Military Review
November-December 2006

Colonel Joseph D. Celeski, U.S. Army, Retired, is a contributing writer and Senior Research Fellow at the Joint Special Operations University, Hurlburt Field, Florida. He has a B.S. from Columbus College, M.A.s from Shippensburg University and the U.S. Army War College, and is a graduate of the U.S. Army Command and General Staff College, the U.S. Air Force Command and Staff College, and the Joint Forces Staff College. He has served in various duty positions in the continental United States, Africa, Bosnia, and the Middle East, to include commanding coalition and joint Special Operations Forces during Operation Enduring Freedom in Afghanistan.

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Attacking Insurgent Space: Sanctuary Denial and Border Interdiction

Denying insurgents operating space attacks is one of the triad of options in irregular warfare (the other two being time and will) that weaker actors employ to take on the strong. Porous borders and spaces for sanctuary, which provide operating space, can prolong an insurgency if the counterinsurgent ignores them or handles them insufficiently. In Afghanistan, while the security line of operation has been effective in enabling friendly social and political processes to proceed, the number one operational dilemma remains the enemy's ability to operate in "ungoverned space" throughout the Pakistani Federally Administered Tribal Area and portions of Baluchistan and to cross the border into Afghanistan whenever he chooses.2 In Iraq, the issue is not so much the sanctuary afforded by Syria and Iran in the classic sense (providing insurgents safe areas for base camps, reconstitution, recruitment, and training), but porous borders that offer insurgents lines of communication, temporary escape, and transnational transit.

This article provides advice about how to attack insurgents in their sanctuaries. It also suggests measures for conducting effective border interdiction. For this study, insurgent sanctuary is defined as an area in a contiguous nation-state used by insurgents for basing and support (versus such in-country sanctuaries as urban areas, rugged terrain, and sympathetic populations). When insurgents enjoy sanctuary, they can become either a persistent irritant to counterinsurgents, or an operational-level problem.

Sanctuary Benefits

Conventional wisdom says that to win, insurgents must gain both internal and external support for their effort. While the target native population can provide a certain level of assistance, mostly intelligence and warning, immediate logistical needs, and temporary safe haven, insurgents face a real challenge if they are cut off from the normal amenities and access to safe venues in which they can rest, refit, and plan. Sanctuary gives the insurgent all that and more: it effectively allows him to neutralize the superior technology, arms, and training of counterinsurgent forces.3 At the same time, insurgent fighters can profit from the physical and moral support of the host-nation government and the local populace inside the sanctuary while their leaders conduct an active, unhindered public relations and information operations campaign to legitimize their cause and build support for it. Criminal activity in or near the sanctuary can also work to the insurgents' benefit. Insurgents can get financial and technological support from criminals in exchange for protection, or use smuggling routes as lines of communication.

Historically, insurgents who have obtained sources of supply and sanctuary and who have operated in favorably rugged terrain have been very difficult to defeat. Conversely, insurgents who did not enjoy sanctuary tended to fail, at least in the security line of operation.

Sanctuary Vulnerabilities

If the advantages of sanctuary and access to border transit are critical to the insurgency, then the sanctuary becomes a center of gravity to be attacked. Insurgents in sanctuary are inherently vulnerable because the government they establish within the sanctuary will automatically threaten their host's sovereignty. Other vulnerabilities include the support they need from the local populace, their sources of supply, and their base defense systems. Insurgents must conduct a fine balancing act to protect all of these vulnerabilities, but their challenge to the host government's authority could be their biggest problem.

In a sense, insurgents hand us a gift when they establish sanctuaries and base camps. Most insurgencies are fought on "human terrain," offering few instances when the counterinsurgent can actually find, fix, and fight the enemy. But when the enemy seeks sanctuary, engagement becomes possible. Once we have located and defined the sanctuary area, we can focus our intelligence, surveillance, and reconnaissance (ISR) assets on it and then, in at least some instances, our combat power. We would be negligent if we didn't force insurgents to earn their pay when they congregated and surfaced. Of course, attacking them in their host-nation sanctuary will require synchronization of military and other government agencies' capabilities at the operational level and higher, to ensure that kinetic actions do not result in defeats in the international court of public opinion.

Insurgents can also be attacked physically when they attempt to enter and leave their sanctuary. They generally do not own their own air transport, so they must transit the sanctuary and contiguous border on foot, mounted on animals, or by a variety of automotive means. At some point, they must physically cross the line demarcating the border. With artful intelligence, we should be able to pinpoint where those lines of transit and crossing points are. This can be accomplished using a combination of human and electronic intelligence.

The third opportunity insurgent sanctuary offers lies on the friendly side of the border. Insurgents in transit require the same necessities as our own soldiers-food, rest, medical support, supplies, access to logistical needs (transport, communications, and weapons), physical security-as they move from sanctuary back into their operational areas. Groups or locations offering these various kinds of support must communicate with one another, and when they do they provide an additional vulnerability for exploitation. Conducting a good intelligence preparation of the battlefield on friendly border areas can yield information on routes of transit, illegal activities flow, supportive populations, rest areas, and possible medical facilities, which can then be targeted or surveilled. Additionally, using such information, analysts can estimate just how far insurgents might travel in one- or two-day increments via their assorted transport modes. The possibility of interdiction can thus be heightened.

Offensive Actions

If insurgents have sanctuary, counterinsurgents must combine a myriad of techniques to win. They must use diplomacy to pressure governments hosting insurgents, conduct combined maneuver with cross-border host-nation security forces, emplace physical or virtual barriers, provide for support and integration of customs and border policing actions, and execute raids into insurgent safe havens. All of these things must be done within the architecture of an effects-based plan.

We continue to look for measures of effectiveness (MOE) in counterinsurgency. At the tactical level, this endeavor is fairly easy because counterinsurgents can quickly identify what works or does not work, and so measure their progress. But when we try to achieve operational-level effects, MOEs become a bit fuzzier, primarily due to many intangibles (for example, the protracted nature of an insurgency, or the human-terrain dimension). Sanctuary denial and border interdiction, though, are two cases of operational maneuver with which the counterinsurgent can seek an effect and hope to achieve measurable results. The means to solve operational-level problems should be effects-based; that is, they should involve getting the enemy to do your bidding while simultaneously attacking to prevent him from accomplishing his goals. We can keep insurgents from protracting the nature of the insurgency if they decide it costs them more to operate from sanctuary than it benefits them.4

Preparing the battlefield. Achieving the effect desired-denial, disruption, interdiction, influence-begins with a careful analysis of the physical nature of the sanctuary and border area. Technology is useful here, particularly 3D terrain-analysis tools combined with space products (to map foliage, hydrography, habitats, movement patterns, weather patterns). Such analysis can assess the terrain to identify likely areas of habitation and potential lines of communication. Overlaid on top of this product should be the lines of criminality and commerce. Finally, a demographic and cultural analysis can be added to complete the picture and determine where insurgents might hide and operate.

The next step is to introduce various ISR methods to confirm the analysis. Physical reconnaissance and emplacement of human or technological surveillance in suspected areas of operation are particularly effective for assessing insurgents' actual use of identified areas of interest. Efforts to verify collection and analysis might include cross-border reconnaissance operations within the enemy sanctuary. One caveat seems necessary here: insurgents will always be more familiar with their sanctuary and lines of communication, so counterinsurgents must remain patient to gain a commensurate level of knowledge.

After conducting thorough analysis and identifying the tools at hand, the third step for the coin strategist is to design a mini-campaign. A variety of methods exist to deny, disrupt, interdict, or influence, but a combination of options-a mosaic-like application of methods-will provide the synergy to attain the desired end-state.

Attack by the host. The best strategy to attack sanctuaries and porous borders is to get the host nation (which may be providing tacit support) to conduct operations and dry up support for insurgents in sanctuary areas. Diplomacy will likely be the means to pressure an otherwise uncooperative host into action. The host-nation security forces then conduct operations within the sanctuary while employing measures to control their borders. In both cases, indigenous operations are much preferred to those conducted by foreign forces, contracted security, or proxies. Host-nation governmental measures are also needed to turn the ungoverned space that makes sanctuaries possible into governed space. At the same time, the host nation government must get at the roots of the populace's active or passive support of insurgents by engaging with the network of local political, religious, tribal, or ethnic leaders. The host nation must also diminish, or provide alternatives to, the criminal enterprises within the sanctuary and problem border areas. Cleaning up these areas will pave the way for the introduction of nongovernmental organizations (NGOs) into the area-and NGOs can be a significant factor in helping to reduce the negative conditions that make sanctuaries possible.

In its attempt to police sanctuary and border areas, the host government may even resort to its own form of unconventional warfare. Whatever the means adopted, counterinsurgents assist the effort by conducting complementary operations on the other side of the border; for example, they might move to interdict insurgents attempting to flee the besieged sanctuary.

Attack the sanctuary. The second measure to deny sanctuary requires physical operations in the insurgent base area with military, paramilitary, or fake guerrilla forces, all achieving the best effect when tailored hunter-killer teams are deployed. These typically long-range, long-duration operations depend greatly on intelligence and stealth. Again, using indigenous forces familiar with the terrain and area tends to lead to bigger payoffs. Rules of engagement need careful crafting for these strikes, to ensure there are mechanisms to govern "hot pursuit."

The French were particularly successful during the Algerian War of Independence (1954-1962) with direct kinetic operations against insurgent Armee de Liberation Nationale (ALN) sanctuaries in Tunisia and Morocco. They employed special tracking teams to hunt down ALN units in the sanctuary areas, and they specifically targeted enemy leadership there in an attempt to cut off the insurgents' head. By combining these operations with ruses (such as setting up fake guerrilla organizations to confuse the real guerrillas and even sow dissension among them) and by skillfully using traitors to lure insurgents, they destroyed the enemy where he lived.

During the Vietnam War, the Military Assistance Command-Vietnam studies and Observation group achieved similar successes. Small indigenous raider forces, ably led by special operations leaders, conducted a variety of missions in Laos and Cambodia to identify, disrupt, and destroy enemy infrastructure. These teams also emplaced sensors and acted as forward observers for air interdiction, thus enhancing their utility.

Attack the border. The third option for defeating an enemy using sanctuary is to interdict the border by emplacing a barrier system. This operation can yield the highest payoff of the three options. When combined with sensor technology and counter-mobility measures, barriers have always been effective against insurgents. Barriers should be backed up in depth with hedgehogs for fortifications, each garrisoned by reaction forces that intercept insurgents who somehow penetrate the barrier. The fortifications don't have to be continuous; they can be reinforced by flying checkpoints and aggressive patrolling.

The axiom that the counterinsurgent must be as mobile as, or more mobile than, the insurgent certainly applies in this operation. Ground mobility for reaction forces can be enhanced by building roads or trails throughout the interdiction-and-denial area. Air mobility-especially helicopters, but also short-takeoff-and-landing aircraft and long-loiter piston planes-can greatly assist the reaction forces too.

Another option in the barrier-fortification area is to employ unmanned Aerial Vehicles (uavs), which are becoming increasingly less expensive and more effective. UAVs can monitor open areas and detect insurgent breaches where counterinsurgent forces are stretched thin. There is a caveat about air assets, however: although air interdiction of sanctuary and border areas can contribute to achieving the effects desired, by itself it has not proven to be highly effective. Therefore, the counterinsurgent's best practice is to synchronize air with other assets.

In setting up and executing a border interdiction campaign, the counterinsurgent can increase his chances of success by enacting population control measures. Such tactics as clearing the population from zones along the border are perhaps extreme, but they can flush out the insurgents (by drying up the sea-the populace-in which they hide and swim) while permitting counterinsurgent forces to use combat power without fear of hitting noncombatants.

The French in Algeria. Two of the best barrier systems ever used to interdict insurgents were employed by the French in Algeria. Once it recognized that the ALN had sanctuaries (complete with barracks, training areas, and medical facilities) in Tunisia and Morocco, the French Army emplaced barriers, zones of interdiction, depopulated the zones, and deployed border maneuver forces to seal off the borders and interdict infiltrators.

The French built the Morice Line along the Tunisian border and the smaller Pedron Line along the Moroccan border. These barrages consisted of hundreds of miles of wire fences Augmented with lights and minefields; over 40,000 troops were assigned to static posts near the barrier. Garrisoned in blockhouses and camps, these troops were backed up by roving patrols and mobile reaction forces. Naval radar technical units were also employed, to detect insurgents and to provide counter-mortar capabilities. All told, French interdiction efforts along the borders and the coast effectively shut down any infiltration by the insurgents and resulted in the isolation of over 30,000 ALN fighters.

Vietnam and McNamara's Line. Critics might point to the ineffective McNamara Line, built by then-secretary of Defense Robert S. McNamara during the Vietnam War to stem North Vietnamese infiltration southward, as evidence that barriers or barrier systems are impractical. This criticism misses the mark, though. Like the Morice and Pedron Lines, the McNamara Line was characterized by physical measures (barriers, outposts, and reinforcing bases), but it was also supposed to have sensors as part of the barrier array. Due to manufacturing problems, the sensor portion of the barrier system was never emplaced, thus creating holes in the Line's detection capability. Ultimately, the same technology was deployed around the Marine base at Khe Sanh, where it proved to be extremely effective.5

Regular border policing. Good governance at the border by the friendly government will buttress counterinsurgent efforts to create an effective border interdiction plan. One of the counterinsurgent's logical lines of operation is "legitimacy or the establishment of governmental institutions." Within this line, consideration must be given to financing and facilitating border security mechanisms (such as border patrols) and the associated customs activities all states employ as signs of their sovereignty. Early on, nation-builders must establish means to restrict the flow of human traffic and trade to key points along the border. Doing so will ultimately enhance the possibility of foiling criminal actions and interdicting insurgents. Technology at key locations can assist in the detection and removal of resources destined for transit deeper within the friendly country's borders. By covering dead space in the crossing area, roving border guards and patrols can deter insurgent efforts to merely bypass any checkpoints.

Tunnels. While all the measures described above are surface operations, care should also be given to detecting underground penetration via tunneling (as we have seen along the southern U.S. border and in the Demilitarized Zone between the Koreas). Finally, just as in the more purely military barrier-interdiction operation, a robust reaction force should be stationed within striking distance of border checkpoints and along suspected transit routes. With enhanced mobility, these forces could react quickly to situations that might overwhelm government border-security forces.

Recent border operations. A successful example of border operations occurred in Iraq in September 2005, when the Iraqi prime minister, Ibrahim al-Jaafari, sealed the northern border with Syria to prevent the infiltration of foreign fighters into his country. Measures taken by al-Jaafari's Interior Ministry included shutting down foot and vehicular traffic (although railway lines of commerce remained open), imposing a curfew in towns near the vicinity of the border post, and conducting combined cordon-and-search operations on the friendly side of the border to root out infiltrators. Predictably, Syria did not assist in these efforts. Had it done so, it would have contributed immensely to the operation's success.6

Concluding Thoughts

Allowing insurgents untrammeled use of sanctuary and the freedom to cross borders enables them to sustain and prolong their rebellion. Whether sanctuaries are permitted willingly or unwittingly by the host nation should not deter the counterinsurgent from attacking, either kinetically or along other security lines of operation. Counterinsurgents do not have to destroy the sanctuary; they can also succeed by disrupting or denying sanctuary and free border transit. When they do the latter, they can seize the initiative from the insurgent and dictate the tempo of combat.

The path to a successful counter-sanctuary campaign lies through the conduct of a well-planned effects-based offensive designed to achieve desired outcomes. Such a campaign must be executed with tailored forces conducting parallel attacks in concert with other lines of operation. This multi-pronged approach will strip away the advantages the enemy gains by hiding behind another country's border; it can turn the sanctuary and the remote border area from a temporary resting spot for insurgents into a final one. In the end, the message is clear: to dry up the insurgency, dry up the sanctuary.


1. Michael a. Sheehan, "Diplomacy," in Attacking Terrorism: Elements of a Grand StratEgy, ed. Audrey K. Cronin and James M. Ludes (Washington, D.C.: Georgetown University Press, 2004), 99.

2. The weakness Pakistan's government has shown in granting autonomy to tribes along the Afghan border has inadvertently created a lawless area, an "ungoverned space" ripe for insurgent sanctuary. Moreover, with a pre-Taliban-era insurgency still festering in Baluchistan, that area appears to be al-Qaeda's and the Taliban's new base from which to conduct attacks into southern Afghanistan (see Tarique Niazi, "Baluchistan in the Shadow of al-Qaeda," Terrorism Monitor iv, 4 (23 February 2006): 3-5.

3. For good contemporary discussions of sanctuary, its benefits, the complications it poses counterinsurgents, and related issues, see Bard E. O'Neill, Insurgency & Terrorism: Inside Modern Revolutionary Warfare, Chapter 4 ("The Environment") (Dulles, VA: Brassey's Inc., 1990); Robert Taber, War of the Flea: The Classic Study Notes of Guerrilla Warfare (Dulles, Va: Brassey's, Inc., 2002); and Anthony James Joes, Resisting Rebellion: The History and Politics of Counterinsurgency, Chapter 17 ("Elements of a Counterinsurgent StratEgy"), (Lexington, Ky: the University Press of Kentucky, 2004).

4. Barry r. Schneider and Lawrence E. Grinter, eds., Battlefield of the Future: 21st Century Warfare Issues (Maxwell Air Force Base, Air University Press, 1998). Key readings on effects-based war and parallel attack can be found in Chapter 4, Colonel John A. Warden III's treatise on "Air theory for the twenty-first century," and Chapter 5, Colonel Richard Szafranski's essay "Parallel war and Hyperwar."

5. Peter Brush, "the Story Behind the McNamara line," Vietnam Magazine (February 1996): 18-24.

6. Jacob Silberberg, "Iraq seals Syrian border; Tall Afar sweep resumes," Denver Post, 11 September 2005, 2a.

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