In late October MSNBC’s Ronan Farrow asked retired Army Lt. Col. John Nagl to give viewers a deeper understanding of the fight between the Islamic State (ISIS) and Kurdish fighters around Kobane. Widely credited with “writing the book” on successful counterinsurgency (COIN) operations, Mr. Nagl said, “we’ve got 1,500 guys on the ground, but they’re not as far forward as they need to be to make a real, immediate impact on the battlefield.” He and a number of COIN experts argue that along with 15,000 U.S. ground troops, Iraqi, Kurdish, and Syrian rebel soldiers can defeat ISIS. Before making any decisions, American leaders should first consider this: despite what is often claimed by a host of advocates, the COIN theories upon which these recommendations are based were in fact demonstrable failures in both Afghanistan and Iraq. We must not sacrifice any more American lives and harm American interests any further by acting on theories that are likely to fail again.

It has been taken as an “obvious truth” by many Americans and major media outlets that the counterinsurgency strategy brought to Iraq by former general David Petraeus in 2007 turned a near-certain defeat into an historic victory. There were two key fundamentals from which many believe victory sprang. The first was that American troops needed to leave U.S. bases and “live in the neighborhoods” with Iraqi citizens, the second that a surge of troops would give Baghdad “breathing space” to form an inclusive government. Instead of leading to success, however, these twin pillars may have contributed to the failure.

In a study published earlier this year by the National Defense University, authors Sterling Jensen and former Iraqi general Najim al-Jabouri wrote this of the Americans’ effectiveness in Anbar province cities: “[t]he surge did not have a role in the Anbar Awakening. Surge troops that came to Anbar in 2007 were not seen as useful… In fact, U.S. troops in general were not seen as useful even before the surge…”

But the authors’ possibly most pointed finding was that the causal factor behind the eventual drop in violence had little to do with either the increase in U.S. troops or the new strategy: “If not for al Qaeda’s murder and intimidation campaign on Sunnis, and its tactic of creating a sectarian war, the Anbar Awakening—a fundamental factor in the success of the 2007 surge—most probably would not have occurred, and it would have been difficult for the United States in 2006 to convince Sunnis to partner with them in a fight against al Qaeda…”

The Sunni-initiated Anbar Awakening, followed by the Petraeus-led “Sons of Iraq” program, resulted in a dramatic drop in violence. The breathing space purchased with considerable American blood was intended to facilitate the development of Iraqi democracy. Kelley Vlahos, contributing editor for The American Conservative, recently wrote, “in hindsight, the only meaningful space created was for Prime Minister Nouri al-Maliki” to use America to rid him of political enemies, not the least of which were many Iraqi Sunni leaders and groups.

Maliki’s oppressive rule, which alienated much of the Sunni population in the Western part of the country, was a key factor in the rise of ISIS; his penchant to dismiss Sunni officers and pack the senior ranks of the Iraqi Security Force (ISF) with inexperienced political patrons played a major role in the disintegration of the ISF when the Islamic State began its offensive.

I served in Iraq as a military trainer in 2009, and have twice deployed to Afghanistan (2005, 2010-11). Between my 2009 Iraq deployment and the last Afghanistan deployment—at the height of that surge—I traveled over 14,000 miles throughout both countries, going on mounted and dismounted patrols, with U.S., allied, Iraqi, and Afghan troops, and led a team to train an Iraqi border battalion. I can conclusively state that outside the wire, the counterinsurgency theories were an unqualified failure at the strategic level. The populations were never protected in either country. The insurgent forces were never fully defeated in either country—and are stronger now than they have been at any time since 9/11. The Afghan and Iraqi governments remain the third and seventh most corrupt governments in the world, and do not have the support of their people. The armed forces for both countries, despite the decade-long effort and tens of billions of dollars that the U.S. spent training them, are virtually incapable of conducting even basic security.

It is incomprehensible that with such an extensive, publicly available record of failure—which cost the United States $2 trillion in direct outlays, 6,842 U.S. troops killed and 52,281 wounded in action—that the designers of this failed concept are given any credibility. The conclusive evidence of the failure is on graphic display right now, in both countries: after six full years and tens of billions spent, the U.S.-trained Iraqi army melted away before a few thousand irregular fighters; after the U.S. pulled out of Helmand province in Afghanistan, the Afghan National Security Forces were incapable of preventing an immediate return of the Taliban.

As the president’s national security team continues to develop a new strategy to deal with ISIS—and now also searches for a new secretary of defense—it is more important than ever to make a no-holds-barred analysis of the past decade of combat experience before settling on a new strategy. No matter how many U.S. boots might be placed on the ground in Iraq or Syria in this current environment, they would not be able to accomplish the president’s previously stated objectives. All the additional causalities we would suffer would be in vain.

We must not send any more Americans into the morass of Iraq and Syria with as little concern as one might show shoveling coal into a furnace. They deserve better than to be asked to risk their lives to conduct a no-win tactical mission.

The opinion expressed in this article are those of the author alone and do not represent the views of the Department of Defense or U.S. Army.

Daniel L. Davis is a Lt. Col. in the U.S. Army stationed in the Washington, D.C. area. He has been deployed into combat zones four times, winning the Bronze Star Medal for Valor in Desert Storm.