The tactical organization of guerrilla units varies according to size and operational demands. Mao called for a guerrilla squad of 9 to 11; his basic unit was the company, about 120 strong. Grivas initially deployed sabotage-terrorist teams of only four or five members. The Greek Civil War of the late 1940s opened with about 4,000 communist guerrillas divided into units of 150 fighters that, as strength increased, grew to battalions 250 strong. Tito began his campaign with about 15,000 fighters organized into small cadres; he ended the war with some 250,000 troops organized into brigades. Vietnamese guerrillas initially were organized into small squads that expanded to battalion and even regimental strengths. As modern guerrilla leaders have discovered, undue expansion may result in security failures and in partial loss of control, as has been the case in Northern Ireland, Colombia, and Palestine. Urban guerrilla units for the most part have remained small and more tightly organized in a cellular structure that, from a security standpoint, has proved valid over the decades—as is witnessed by the September 11 suicide attacks by al-Qaeda.

Protracted revolutionary warfare demands a complicated organization on both political and military levels. Mao early developed a clandestine political-military hierarchy that began with the cadre or cellular party structure at the hamlet-village level and proceeded to the top via district, province, and regional command structures. This was roughly the concept followed by guerrilla forces in Malaya and Indochina. Tito was careful to build a parallel political organization in areas that came under his control as a foundation for his future government. Other guerrilla leaders formed civil organizations to provide money, supplies, intelligence, and propaganda. The Viet Cong, Algerian rebel groups, and the PLO established provisional governments in order to win international recognition, financial backing, and in some instances recognition by the United Nations.

Divisions within political and military commands stemming from ego, envy, ambition, greed, and ignorance have plagued guerrilla leaders through the centuries and are probably more responsible for failed insurgencies than any other factor. The Algerian rebellion of the 1950s suffered severely until the National Liberation Front either absorbed or neutralized rival guerrilla groups, but it failed to settle feuds between the Arabs and the Berbers or between its own internal and external commands. Colombian rebel groups are frequently in conflict. The IRA lost a great deal of effectiveness when it splintered in 1969. Chechnyan rebels are divided between Islamic extremists, who insist on gaining an independent state ruled by Sharīʿah law, and orthodox guerrilla fighters, including those who favour an autonomous government under Russian rule. The Tamil Tigers in Sri Lanka are believed to be divided between Prabhakaran’s hard-liners, who demand a separate state, and moderates, who want peace and would accept a reasonable autonomy. At least three major rebel groups and numerous splinter groups are at work in the Philippines, including Islamic fundamentalists, moderate Muslims, and communists. During the Afghan War against Soviet occupation in the 1980s, a score or more of mujahideen rebel groups, ranging from a few hundred to several thousand fighters, were held precariously together by the Islamic religion, an infusion of several billion U.S. dollars, enormous profits from the opium trade, and the desire of each warlord to enlarge his traditional turf. Scarcely had the Taliban government been overthrown by U.S. and allied forces in late 2001 than the warlords turned on one another and on the newly established central government, creating a dangerous semi-anarchy.

Arms

The guerrilla by necessity must fight with a wide variety of weapons, some homemade, some captured, and some supplied from outside sources. In the early stages of an insurgency, weapons have historically been primitive. The Mau Mau in Kenya initially relied on knives and clubs (soon replaced by stolen British arms). French and American soldiers in Vietnam frequently encountered homemade rifles, hand grenades, bombs, booby traps, mines, and trails studded with punji stakes soaked in urine (to ensure infection). Nearly every guerrilla campaign has relied on improvisation, both from necessity and to avoid a cumbersome logistic tail. Molotov cocktails and plastique (plastic explosive) bombs are cheap, yet under certain conditions they are extremely effective. Stolen and captured arms also traditionally have been a favourite source of supply, not least because army and police depots also stock ammunition to fit the weapons.

The worldwide proliferation of weapons during the decades of the Cold War added a new dimension to guerrilla capabilities, as the superpowers and other states provided modern assault rifles, machine guns, mortars, and such sophisticated weapons as rocket-propelled grenades and antitank and antiaircraft missiles. The collapse of the Soviet Union and the transformation of some of its republics into independent states brought on a fire sale of more weapons. Many other weapons, however, also came from the busy arsenals of the United States, the United Kingdom, France, Germany, Russia, and Israel.

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This largesse has proved to be a double-edged sword for rebels. Although it has improved their staying power, it has also produced an unwanted financial and logistic requirement to feed the hungry weapons and at times has led to quasi-conventional set-piece battles—usually to the guerrillas’ regret.

Sanctuary and support

It was axiomatic to Mao and his followers that revolution begins in familiar terrain. Once sufficient base and operational areas are established, guerrilla operations can be extended to include cities and vulnerable lines of communication. This rural strategy may be influenced by such factors as political goal, geography, and insurgent and government strengths.

If a guerrilla force is to survive, let alone prosper, it must control safe areas to which it can retire for recuperation and repair of arms and equipment and where recruits can be indoctrinated, trained, and equipped. Such areas are traditionally located in remote, rugged terrain, usually mountains, forests, and jungles.

Sympathetic neighbouring countries may also provide sanctuary, both as a physical redoubt and as a source of material support. Ho’s guerrillas, in the later stages of the war against France, relied on China for refuge, training, and supply of arms and equipment; later, in the war against the United States, they used Laos and Cambodia for sanctuary. Still later Thai guerrillas found sanctuary and support in Cambodia, as did Nicaraguan guerrillas in Honduras. Palestinian irregulars have often enjoyed refuge in Arab states bordering Israel, and a wide variety of militant groups found refuge in Afghanistan during the 1990s. For years the Basque ETA terrorists took cover in France. Islamic terrorists in the Philippines routinely lose themselves in the jungles of small southern islands. Chechnyan guerrillas frequently find sanctuary in the neighbouring republic of Ingushetia and in Georgia.

People offer a final form of sanctuary, one especially important to an urban guerrilla employing terrorist tactics. A sympathetic population can turn a blind eye to guerrilla activity, or it can actively support operations. During the Cypriot war Grivas was surrounded by a British force for nearly two months without being captured. An Algerian rebel leader installed himself within 200 yards of the army commandant’s office in Algiers. The position of neither rebel leader was betrayed despite generous inducement offered to collaborators. An outstanding example from more recent times is the disappearance of Osama bin Laden and Taliban leader Mohammed Omar despite an intensive manhunt and a reward of $25 million for information leading to their capture. On May 2, 2011, bin Laden was killed in a U.S. special forces raid after nearly a decade at large; Omar died in 2013, but his death was not revealed for more than two years.

Terror

Terror is one of the most hideous characteristics of guerrilla warfare yet one of its most basic and widely used weapons. It is employed on several levels for several reasons. Tactically, its purpose is to intimidate the military-police opposition—for example, by slitting the throat of a careless sentry or by tossing a grenade into a provincial police outpost. At a slightly higher level it is used to eliminate political and military leaders and officials in order to destabilize the government; to persuade the general populace to offer sanctuary, money, and recruits; and to maintain discipline and prevent defections within the organization. On a still higher level it is used to focus attention on the rebel cause with the hope of winning international support (including financing and recruits) while maintaining internal morale.

It is important to note that up to a certain point the use of terror, though condemned by orthodox governments, is expected and is also a major tactic in counterguerrilla warfare. But what is that certain point? Public opinion seems to put it at promiscuous murder, as exemplified by bomb attacks, whether suicidal or otherwise, against civilian targets. In defense of such attacks, terrorists point to their debilitating effect both in destabilizing governments and in bringing on excessive military reprisals that cost the government public support. What guerrillas risk in such attacks, however, is crossing a line that the public draws between guerrilla fighters and common criminals.

Not all guerrilla leaders have favoured the use of such extreme tactics, either because of humanitarian concerns or because they realize that the resultant stigma outweighs the psychological gains. In Palestine the Haganah broke with two other Zionist militias, Irgun Zvai Leumi and the Stern Gang, over the issue. In Ireland IRA leaders had sharp disagreements on the use of extreme terror, which resulted in a movement divided between “official” and “provisional” wings, along with numerous splinter groups. Although the PLO denounced the use of such tactics, Ḥamās, Islamic Jihad, and al-Aqṣā Martyrs Brigade continued to employ them on the grounds of justifiable retaliation for military terrorism—as did other groups in Chechnya, Spain, the Philippines, and elsewhere, while also using them for purposes of intimidation and identification.

It is difficult to assess the psychological impact of criminal terrorism on the general population, but it appears that even those persons passively sympathetic to a guerrilla cause are slowly alienated by terrorists planting bombs in shopping centres and holiday resorts or blowing passenger aircraft out of the sky. The sea change in public opinion may have come with the September 11 aerial suicide attacks against American targets and with the United States’ subsequent “war on terror.” After September 11, 2001, guerrilla warfare, no matter the form or purpose, was generally judged by Western and some Eastern countries to be anathema. Law-enforcement agencies and military forces around the globe were enlarged and adapted to fight terror—literally and with no holds barred. The unforeseen results have been several, but the most unfortunate one has been the use of the war on terror as a shield for continuing abuses by the military, paramilitary, or police in fighting domestic insurgencies. The result is ironic: the more repressive the military terrorism, the greater the number of moderates who come to sympathize with extremists and turn a blind eye to their murderous attacks—a vicious cycle sadly illustrated in the Israeli-Palestinian conflict as well as conflicts in Sri Lanka, the Philippines, Chechnya, Indonesia, Northern Ireland, and elsewhere.