Last week President Trump delegated to Secretary of Defense James Mattis the authority to determine how many more troops to deploy into Afghanistan. Mattis has reportedly settled on 4,000. He claims that this will help end the stalemate in that war. He is wrong. This deployment will have no impact on the outcome of the 16-year-old war in Afghanistan, but more importantly, continues a troubling trend in U.S. foreign policy: The military move has no ties to a strategic outcome.

Astonishingly, the day before the increase in troop strength was announced by the White House, Mattis admitted in testimony before the Senate Armed Services Committee that the United States was in a “strategy-free time and we’re scrambling to put it together.” As should be clear by now, the problem isn’t the number of troops, but in the fact the military is being used, without a strategy, to solve a political problem. Until Washington comes to grips with this fundamental error, it is a virtual certainty that the use of force abroad will continue to fail in its attempt to accomplish strategic objectives. Let me explain why.

Throughout my military career, I fought in high-end tank warfare, served in counterinsurgency operations, and performed duty as a foreign-military trainer. I also served on the staffs at the division level, corps level, and in the Pentagon. Since retirement, I have traveled multiple times to the Middle East as a civilian. In short, I have observed or participated in a broad spectrum of combat operations and observed the formation of policy from the lowest to highest levels.

I can say with a high degree of confidence that Washington’s reliance on the military instrument to solve international problems has served to degrade national security.

Everything Americans see or read reinforces that U.S. troops are the most capable, lethal, and powerful in the world; they succeed everywhere they are sent. The unstated assumption, however, is that tactical success equals strategic success. If our troops accomplish their mission, the thinking goes, then the purpose of their mission must also be a success. But that is an incorrect assumption.

The insurgent enemy we engaged in Operations Enduring Freedom and Iraqi Freedom would often succeed in killing American troops with the ubiquitous roadside bombs (IEDs), but in recorded engagement between U.S. troops and insurgent fighters, American and NATO troops won 100 percent of the time. Every training team that was deployed to train Afghan and Iraqi troops or policemen succeeded in improving the ability of those they trained in all cases. Yet tactical success cannot achieve strategic success because the problems which plague these countries are political and diplomatic, not military.

If we are to solve these problems with military force, every mission—whether a small raid of an enemy outpost or a major deployment of multiple combat brigades—has to specify what the operation is expected to achieve, how the commander plans to accomplish the mission, and what the senior commander or policymaker desires as an end state. In other words, what conditions does he or she want to exist on the ground after force has been used? Without this information, how will either the policymaker or the American people know whether the mission was a success?

For example, the closest Obama came to articulating a stated mission for the military was when he authorized our armed forces to engage ISIS in Syria. In February of 2015, then-President Obama said, “I have directed a comprehensive strategy to degrade and defeat ISIS. As part of this strategy, U.S. military forces are conducting a systematic campaign of airstrikes against ISIS in Iraq and Syria.”

The statement did not explain what the “systematic campaign” of airstrikes was intended to accomplish. How did the president define “degrade”? What metric would be used to assess when ISIS was “destroyed”? No criteria were ever presented to the American people. As a result, it was impossible to ever know if the strategic mission was a success or an abject failure.

The vast majority of the resulting airstrikes indeed hit their targets. But to what end?

If even the commander-in-chief does not know what the force is expected to accomplish, the ground commanders’ efforts are literally shots in the dark. They may kill a great many enemy fighters but achieve nothing of strategic value. That is in fact what did happen. Sadly, such obscure outcomes have become the norm.

The Iraq surge succeeded brilliantly on the tactical level, but had no effect on the political dynamics in Iraq. Internal and toxic political actions in Baghdad laid the groundwork for the weakening of the Iraqi Security Forces and the rise of ISIS.

The Afghan surge likewise succeeded in temporarily reducing the level of violence, drove the Taliban out of Helmand and Kandahar provinces, but had no effect on the corrupt level of governance in Kabul, nor the support to insurgents provided across the border by Pakistan—and the Taliban has since recaptured entire swaths of both provinces.

U.S. airpower devastated the regime in Libya in 2011 but could not influence the political strife that followed. All three countries are currently embroiled in vicious civil conflicts with little hope of near-term resolution.

Today’s active military missions against ISIS in Mosul and Raqqa are virtually guaranteed to suffer the same fate. We have the ability to employ military power to affect the removal of ISIS from both cities. The successful accomplishment of those tactical missions, however, will have no effect on what happens politically in the aftermath.

Washington will have little to no influence on who rules in Raqqa after ISIS is eventually driven out. The U.S. will not be able to direct power-sharing agreements among the various militias participating in the fight—or prevent Turkey, Iran, the Syrian regime, al-Nusra, or any of a dozen other radical Islamic groups from battling for control of Raqqa. It is very possible that after the successful accomplishment of our tactical objectives of routing ISIS from those cities, a new round of violence will engulf both.

Changes are clearly required in American foreign policy. The first opportunity to begin correcting past deficiencies is cancelling the increase in troops the administration is considering sending to Afghanistan. The White House must do more than announce what tactical missions the troops are expected to execute. They must articulate what strategic outcome these troops are expected to attain. There is little doubt every combat mission will succeed, but the president must explain what end-state he desires in Afghanistan. Before asking more U.S. soldiers to put their lives on the line, the president must explain what success will look like.

If no one can articulate to the American people and our service men and women what military force is expected to achieve, the sword must remain sheathed. We must end the bad habit of using lethal military power that routinely fails to improve American national security.

Daniel L. Davis is a senior fellow for Defense Priorities and a former Lt. Col. in the U.S. Army who retired in 2015 after 21 years, including four combat deployments. Follow him @DanielLDavis1