Most war theorists conceive of war as a contest of wills. Put another way, the party who wants it most—and will thus sacrifice the most—usually wins in the long run. Consider, for instance, a group of mujahideen repelling the Soviets after a decade of fruitless bloodletting in Afghanistan. Or, for that matter, consider some of the same fighters showing NATO the exit a generation later. War’s fundamental character has not changed over time, and the contest of wills remains a bedrock principle. To apply the concept, consider what the average ISIS fighter would do to secure the success of the Islamic State against what the average American would do to roll it back. As things stand, the ISIS fighter is considerably more committed to his cause—particularly in the absence of convincing proof that ISIS poses an existential threat to the American way of life—and only 1 percent of Americans are actually involved in the so-called war on terror. In both of America’s greatest military successes in the twentieth century—the world wars—America came late, but with a total mobilization that called on the resources of a significantly larger proportion of the population. Moreover, that population was considerably more unified in purpose.

Additionally, expeditionary wars on foreign soil represent challenges on several fronts. Deploying and supporting troops, heavy machinery and the routine supplies of war, especially over great distances into landlocked countries with rugged terrain, complicates logistics. This is also expensive and relies on the continued support of the citizenry back home. The expeditionary force is most often at a disadvantage in that it must secure victory while fighting far from home. Its opponents, comfortable on their home soil, do not have to win—they just have to wait out the invading force and not suffer catastrophic battlefield defeat.

During the American Revolution, George Washington employed a Fabian strategy against the expeditionary British force. Washington avoided large engagements on unfavorable terms, as his goal was to preserve a true fighting force and wear down his enemy until Westminster decided to stop throwing men and material at the Continental Army. The militarily superior British pulled the plug on their colonial undertaking after six years of active fighting in North America. They had other strategic considerations and made a difficult choice to concede defeat in the North American theater of a larger war. Unfortunately, today Washington has more in common with Westminster: it holds a losing hand against a determined enemy pursuing a Fabian strategy. The British experience in America suggests that a professional military in an expeditionary capacity may come up short.

RECENT MEDIA coverage of daily life inside of the Islamic State suggests that U.S. officials should not be so condescending as to think that those living under harsh ISIS rule are mere sheep awaiting rescue. The millions of Iraqis and Syrians now living under ISIS domination far outnumber their new masters. Those under ISIS rule have few good options, and the costs of rash action are high. The Iraqi army is apparently unable to retake any of ISIS core territory, at least not without the help of American airpower, advisors and (most problematically) Iranian-backed Shia militias. It is perhaps not a foregone conclusion that Sunnis living in the Islamic State would prefer militias backed by Iran’s Quds Force as their liberators from ISIS. They may well view this sort of “liberation” as out of the frying pan and into the fire.

Although patience in a twenty-four-hour, crisis-to-crisis news cycle is notable for its absence, given time some promising developments in ISIS territory could come to pass that undermine the Islamic State from within. Any lasting governing entity relies on some level of support or at least consent of the governed. The actions of ISIS toward its subjects suggest that over the long term they might not achieve this. Fear and brutality only go so far. Parents fed up with their children being indoctrinated with fundamentalist hate at school, women who cannot leave the house with their faces uncovered or without male relatives, men who are being extorted for ISIS taxes, citizens disgusted by summary executions and floggings, fathers who dread their sons becoming brainwashed to be martyrs and mothers who want their daughters to enjoy equal rights will begin to find common cause against the Islamic State. They may decide to cautiously provide tips to the Iraqi army’s special forces on the locations of ISIS leaders or their weapons caches. They may themselves begin to hide weapons and supplies for when the popular mood shifts.

To use a parallel from the American Revolution, those under ISIS rule may form their own Iraqi committees of correspondence, Iraqi Sons of Liberty and Iraqi minutemen. They may seek their own outside allies and develop their own internal intelligence networks. In short, they will eventually resist, as the early sparks of the ill-fated Arab Spring will attest. From the Orange Revolution to the Prague Spring, from the Polish Solidarity movement to the Warsaw Ghetto uprising, the oppressed eventually resist. The desire for life, liberty and the pursuit of happiness is not exclusively American, but Americans cannot be the sole guarantors either. History has shown that peoples who perceive themselves to be oppressed usually organize into a creditable rebellious force, although this usually takes years for suitable levels of organized frustration to congeal into a counterforce.

As in the American Revolution example, defeating a superior force often requires powerful allies. The French contribution to the American war effort was a key development, but the French refrained from becoming openly involved until after the American victory at Saratoga in the fall of 1777. It was only after the Americans proved to be a formidable fighting force and fully devoted to their cause that the French arrived. Indeed, foreign military assistance and training for “internal defense” can be critical to success, but first the will and ability to win must be convincingly demonstrated. An increasingly vocal minority of Americans, whom we now refer to as “Patriots” and “Founding Fathers,” spent the greater part of the early 1770s organizing themselves and secretly preparing for violence.

CONSIDER A familiar scenario, so familiar that it reads like many recent headlines from Iraq: Enemy forces are gaining momentum and seizing territory at an alarming rate. They have a stronghold in the shape of a triangle just over an hour’s drive from the capital. With the political dysfunction in the capital city and, even after American training, local troops underperforming, it seems that only an American-led search-and-destroy mission could root out the enemy, protect the capital and shift the battlefield momentum. After a period of airstrikes, American armored and helicopter-borne infantry forces duly arrive in the insurgent triangle and for three weeks attempt to clear the area of enemy forces, but they are unable to discern civilian from insurgent—it’s possible they are one and the same, but absent uniforms or a recognizable chain of command, they are uncertain. These American troops are killed by booby traps and snipers, but never identify the enemy. Eventually declaring the area “cleared,” American soldiers destroy some enemy weapons caches, and American senior officers brand it a successful operation.

No, the above scenario isn’t Baghdad, the nearby Sunni Triangle, the crumbling Iraqi National Army and the advancing Islamic State. The year was 1967 and the operation, called Cedar Falls, was to be the largest of the Vietnam War. Its purpose was to clear the “Iron Triangle” of Viet Cong irregular forces that were threatening Saigon—a nearly failed state propped up by American power. Frustratingly, the enemy would not stand and fight in the face of overwhelming American tactical and material superiority. The Viet Cong forces moved across the porous border into Cambodia and simply returned when the American forces departed the area. After the operation had ended, and at the cost of more than four hundred American casualties, many senior American officers counted Cedar Falls as a success, pointing to the numbers of weapons stockpiles that were destroyed and the fleeing enemy. In retrospect, the failure of Cedar Falls was emblematic of American efforts in Vietnam. In reality, the residents of the Iron Triangle, much like their countrymen throughout the rest of South Vietnam, found aspects of the Viet Cong message appealing, and surely no worse than the repressive and corrupt government in Saigon.

In hindsight, the theory that Vietnam’s fall to the Communists would make the rest of Asia topple like dominos into the Soviet sphere proved to be alarmist and false. Further, what appeared in 1965 to be in America’s core national-security interests was identified by 1970 as irrelevant, a significant diversion of American resources from more pressing concerns and a major source of political and social tension on the home front. American political leaders declared that the Republic of Vietnam should be responsible for its own security and promptly began a period of “Vietnamization,” in which American forces trained and equipped the South Vietnamese military, paving the way for an American withdrawal. Saigon fell two years after the American withdrawal, but that would have happened no matter what year the Americans finally decided to pull the plug. This is worth remembering when hawks seek to blame the Obama administration for the current state of affairs in Iraq because it pulled out American troops in 2011. Even if the United States had kept thousands of troops in Vietnam until 1983, Saigon would have fallen by 1985. Political problems can be papered over with military force for a long time, but in the end the result is the same.