Just war aims at peace. As Augustine argued, “Every man seeks peace by waging war, but no man seeks war by making peace.” We do not fight war for its own sake, or for revenge, profit, or prestige. The only conceivable rationale for waging war is to create a world of better, deeper, more lasting peace than the one that led to war in the first place.

For example, after the United States defeated Germany and Japan, it occupied, administered, and rebuilt those countries. That is what fighting war for the sake of peace looked like after World War II.

The United States is engaged in a war against jihadists. The war started at least as early as 1998, when al-Qaida bombed two U.S. embassies in Africa, though one can find roots as far back as the 1979 Islamic Revolution in Iran. The intellectual roots of jihadist thought go back much further, to the founding of the Muslim Brotherhood in Egypt in 1928, but jihadists did not target the United States until more recently.

In response, the United States has built the most powerful military force, and the most effective man-hunting capability, in the history of warfare. The U.S. military has essentially perfected the art of finding and killing human beings. It sounds bloodthirsty, but killing jihadists is just: it is the simple right of self-defense against a fanatical and totalitarian movement that seeks aggressive expansion and conquest. Americans who flinch at the bluntness of this moral calculus are lying to themselves about what war involves.

We are called to love both our enemies and our neighbors. When our enemies attack our neighbors, stopping our enemies is an act of love for both: we love our neighbors by working for their safety, and we love our enemies by minimizing the evil they commit. Augustine argued that when “men are prevented, by being harmed, from doing wrong, it may be said that a real service is done to themselves… For the person from whom is taken away the freedom which he abuses in doing wrong is vanquished with benefit to himself.”

But the United States failed to build peace, in large part because of the under-resourced stabilization operations and, subsequently, premature withdrawals from Iraq and Afghanistan. After long and costly counterinsurgencies, both countries are still in turmoil. Jihadist groups—al Qaida, the Taliban, the Islamic State, Jabhat al-Nusra, and many others—are stronger, more popular, and more widespread than at any point since before 2001. Other jihadist groups are similarly gaining ground in Pakistan, Yemen, Somalia, and Nigeria, among others. By almost every metric, the United States is losing the war against jihadists.

Social scientists sometimes talk about “revealed preference.” What they mean is that, by studying patterns of behavior, we can infer the persistent motivations behind that behavior. Over the last 15 years U.S. policymakers have demonstrated their “revealed preference” for their strategy against jihadist groups: they prefer to kill as many as possible, at as low a cost and with as little risk as possible, and they have little to no interest in fostering a just and lasting peace in the regions where jihadists operate.

This grand strategy against jihadism is both immoral and ineffective. It is immoral because, if we don’t aim at peace, we aren’t going to get it. Political violence without concern for any sort of political settlement that might take hold is not just war; it is brute force married to the hope that enough killing will simply make the problem go away. This should give any morally serious person pause.

For example, Senator Ted Cruz recently pledged to “carpet-bomb” ISIS into “oblivion,” but, separately, has argued that the U.S. should avoid reconstruction and stabilization operations. Taken together, Cruz’s foreign policy worldview is exactly the kind that would succeed in killing—indiscriminately, by the way—but fail in anything else. His approach would prolong conflict, not resolve it, by leaving underlying political and social conditions unaddressed.

There is another unintended casualty of this approach to war. Leaving large swaths of the world embroiled in violence will require the United States and other western governments to tighten internal security to prevent terrorist attacks at home. This means ever-stronger domestic surveillance and intelligence gathering. Advocates of limited government and strong civil liberties should be the strongest advocates of a different approach to war.

The problem will not go away. A grand strategy of endless killing is ineffective. Jihadists flourish in conditions of chaos, violence, civil war, state failure, and privation. The United States is currently sustaining an indefinite worldwide assassination campaign against anyone it deems to be a terrorist, anywhere in the world, with no end in sight, and with no attempt to address the endless violence in the Middle East and South Asia that gives rise to the culture of jihadism in the first place. Jihadists are the perfect Hydra: we can kill them one by one, for decades, and never win.

As David Petraeus famously asked, how does this end? It ends when the United States and our allies live up to our responsibilities to foster peace. In Syria and Iraq, that means the Islamic State—or its successors—are unlikely to be finally and definitively defeated until there is a political settlement in the region. Indefinite bombing without a political strategy will prolong, not end, the conflict.

A political settlement must be backed up by massive foreign aid and enforced by a substantial armed force—preferably, Syrian and Iraqi armed forces accountable to decent governments, but an international force if not. The same is true in Afghanistan and Pakistan, which is why I have long argued that a U.S. commitment to those countries is obligatory if we intend the war there to have been justly fought and won.

A century ago the United States won World War I but lost the peace by abdicating its responsibility, sowing the seeds for the outbreak of a much greater war two decades later. Today, history will likely see the withdrawals from Iraq and Afghanistan as the Versailles of the War on Terror, political failures that seized strategic defeat from the jaws of military victory. It is nearly certain that political violence will continue to emanate from both regions, exporting instability and terrorism for the foreseeable future because of the United States’ failure to build peace.

In Iraq at least, the turmoil has already sown the seeds for another conflict. If the war in Syria and Iraq goes unaddressed, we are only kicking the can down the road and guaranteeing that when we eventually intervene, it will be harder, costlier, and riskier than necessary. Americans are weary of war and unlikely to show enthusiasm for sustained engagement, let alone increased foreign aid, security assistance, and military deployments, in either region. But such a commitment is required if the United States is to end jihadism and build a just and lasting peace.

Follow Paul D. Miller on Twitter.

Dr. Paul D. Miller is the associate director of the Clements Center for National Security at The University of Texas at Austin and a research fellow at the Ethics and Religious Liberty Commission. He previously served as Director for Afghanistan and Pakistan on the National Security Council staff under Presidents George W. Bush and Barack Obama.

Photo Credit: U.S. Navy. ARABIAN GULF (Dec. 28, 2015) An F/A-18E Super Hornet assigned to the “Fist of the Fleet” of Strike Fighter Squadron (VFA) 25 prepares to launch from the flight deck of the aircraft carrier USS Harry S. Truman (CVN 75). The Harry S. Truman Carrier Strike Group is deployed in support of Operation Inherent Resolve against Islamic State (ISIS), maritime security operations, and theater security cooperation efforts in the U.S. 5th Fleet area of responsibility. (U.S. Navy photo by Mass Communication Specialist 3rd Class B. Siens/Released)