In recent history, very few counterinsurgency wars have ended in success. Guerrillas are often outgunned by a wealthier invading power, but they do have two powerful advantages. One is that they are fighting on their home turf, which they usually know much better than the invader. Guerrilla warfare at the strategic level is defensive, even though at the tactical level, raiding insurgents are many times on the offense. As a result of being on the strategic defense, the second advantage is that the attacking power will find it difficult to overcome the "foreign invader" label among the population of the invaded country. Thus, because winning the support of the local population is the most important—and difficult—objective in any counterinsurgency war, most such campaigns end in failure.

But there have been a few notable exceptions. At the turn of the 20th century, the United States refused independence to the Philippines after the Spanish-American War and then outfought Filipino guerrillas to make U.S. colonial rule stick; a U.S.-supported Greek government beat back communist insurgents in the late 1940s; and the British beat back Marxist guerrillas in Malaya in the late 1940s to the early 1960s. Although it might be tempting to assume that the only way to beat guerrillas is to use ruthlessly brutal tactics, this predominated in only the first of the three episodes. The United States used concentration camps, torture, and a scorched-earth policy in taming Filipino guerrillas. But even here, such drastic and unacceptable methods may not have been what tipped the outcome to a counterinsurgency success.

The common thread in these three success stories seems to be that either the guerrilla movement was divided or did not win the overwhelming support of the local populace. In the case of the Filipino insurgency, Emilio Aguinaldo, the guerrilla leader, never really had the support of most of the Filipino population. Similarly, in Malaya, the rebellion occurred only in a minority of the minority Chinese population, thus allowing the British to eventually stamp it out. In Greece in the late 1940s, the opposition movement was divided, allowing the U.S.-backed Greek government to prevail.

How do these conclusions apply to current counterinsurgency wars? In both the rugged terrain of Afghanistan and the urban landscape of Iraq, guerrilla groups have taken advantage of familiar environments to effectively harass the U.S. superpower. In addition, the United States, in some sense, has been more restrained than the Taliban and Iraqi insurgents toward the local populations. The Taliban is known for its harsh methods of justice and killing, and some of the Iraqi guerrillas have slaughtered civilians with suicide bombs. In contrast, in both nations, the United States has built infrastructure projects and handed out candy to children. Yet the United States has failed to win the hearts and minds of either population, because of excessive collateral killings from air and ground attacks. At the end of the day, even a foreign invader who tries to be more sharing and caring is still regarded as a foreign invader.

In Somalia, the militant Islamist Shaabab movement had little public support until the United States, as part of its global "war on terror," began funding unpopular and corrupt Somali warlords to promote "stability"—turning the local population toward the movement and away from the perceived meddling superpower and its Somali government lackey. Then, making things worse, a U.S.-backed Ethiopian invasion provided only some temporary stability as long as Ethiopian troops were willing to occupy the country. The cross-border invasion by Ethiopia—long regarded by Somalis as their archenemy—to quash the militant Islamists only enhanced the radicals’ standing in Somalia once Ethiopian forces withdrew. In short, history shows that the presence or influence of foreigners only feeds the flames of any insurgency, which can then be portrayed as a defense of the nation against outside aggression.

But isn’t there hope for Iraq and Afghanistan because opposition forces are divided and often unpopular? Not really. In Iraq, the United States was able to take advantage of al-Qaeda-in-Iraq’s brutal killing of civilians to divide the Sunni guerrilla movement and bribe the Awakening Councils to battle the group. The problem in Iraq is that as U.S. forces draw down, the now reduced guerrilla war could turn into a civil war among the Sunni, Shi’ite, and Kurdish ethno-sectarian groups. In Afghanistan, the Taliban is unquestionably brutal, but Afghans do regard the United States as a foreign occupier, are suspicious of the U.S. long-term military presence, do not support a surge in U.S. forces, do not think it will defeat the Taliban, and thus support negotiating with the insurgents. In short, the prognosis is not good in either case.