In August 2017, President Donald Trump rubberstamped his predecessors’ failed policies when he announced America’s recommitment to the mission in Afghanistan. In his speech, Trump made the same promises of victory and signed on to the same set of goals outlined many times by President George W. Bush and President Barack Obama:

Our troops will fight to win. We will fight to win. From now on, victory will have a clear definition: attacking our enemies, obliterating ISIS, crushing Al Qaeda, preventing the Taliban from taking over Afghanistan, and stopping mass terror attacks against America before they emerge.

Trump’s plan for victory in Afghanistan was dead on arrival. Based on the same faulty premises about the threat of terrorism and the benefits of military action, Trump’s Afghanistan campaign has done little to make Americans safer.

None of this is news. By the time Trump made his announcement last year, the fundamental indicators of failure in Afghanistan had been easy to see for quite some time. Why has the United States embraced the same feckless strategy over 17 years and three presidents?

The answer is simple: Washington’s continued embrace of a host of strategic myths.

The safe haven fallacy has promoted unwarranted concern over the threat of future terrorism. When Trump asked why the United States needed to stay in Afghanistan, Secretary of Defense James Mattis responded, “to prevent a bomb from going off in Times Square.” And indeed, many argue that the failure of terrorists to launch a second 9/11-style attack proves the value of continued American efforts in Afghanistan and military action elsewhere. In his August 2017 speech, Trump made it clear that this argument was central to his decision to extend the American commitment to Afghanistan, noting,

The consequences of a rapid exit are both predictable and unacceptable. 9/11, the worst terrorist attack in our history, was planned and directed from Afghanistan because that country was ruled by a government that gave comfort and shelter to terrorists. A hasty withdrawal would create a vacuum that terrorists, including ISIS and al Qaeda, would instantly fill, just as happened before September 11th.

Despite its popularity in Washington, the safe haven argument is overblown. The most important base of operations for the 9/11 terrorists was not Afghanistan, but the United States. As the 9/11 commission report describes, all of the hijackers entered the United States legally, where they received their technical (pilot) training, not in some clandestine Afghan camp. Without the ability to carry out their preparations here in the United States, the 9/11 attack might not have occurred.

Post‑9/​11 security reforms have made it far more difficult for terrorists to enter the United States, and they now are unable to access such sophisticated training without raising suspicion. These efforts, not the campaign in Afghanistan, have been the most effective in curtailing the ability of would-be terrorists to carry out attacks on U.S. soil.

More generally, the safe haven fallacy is an argument for endless war based on unwarranted worst-case scenario assumptions. To worry about an attack from Afghanistan, a capable terrorist group must have room to operate there safely, must decide a major attack on the U.S. homeland is a good idea, and must figure out a way to carry out that attack from Afghanistan — 7,000 miles from the American homeland — without the sort of support within the United States that al-Qaeda enjoyed in 2001. And all of this must occur without the United States detecting and disrupting the plot.

Though the defense establishment gets paid to plan for trouble, this series of events is so unlikely it does not justify the occupation of Afghanistan today or tomorrow. If the United States left Afghanistan and the Taliban took control again, why would they provide support to Al Qaeda, the Islamic State, or some other group with plans to repeat 9/11? The Taliban did not attack the United States, and they certainly did not benefit from al-Qaeda’s strike on the United States. Moreover, leaving Afghanistan does not mean the United States has to ignore what is happening there. Intelligence can provide early warning should events someday point toward the possibility that a major attack on the United States is becoming more likely. At that point the United States could intervene in a more limited fashion to deal with gathering threats.

The belief that terrorism and the conflicts and animosities which give rise to it can be eradicated is the second myth propagating the effort in Afghanistan. Trump’s promise to obliterate the self-proclaimed Islamic State and crush al-Qaeda, while emotionally satisfying, is strategically misguided. The roots of terrorism, like the causes of war, run too deep for even a superpower to do much about. Defeating al-Qaeda and the Islamic State will not put an end to jihadist terrorism because the organizations themselves are simply the symptoms of underlying political dynamics and fundamental social and cultural conflicts, not their cause. Declaring war on these symptoms and intervening in nations riven by conflict is a recipe for failure.

The evidence indicates America is further from defeating jihadist groups than it was on Sept. 12, 2001. Despite 17 years in Afghanistan, almost as long in Iraq, as well as drone strikes and special operations missions in Syria, Pakistan, Libya, Somalia, Yemen, the Philippines, and Mali, the State Department reports that the number of Islamist-inspired terrorist groups has tripled since 2001, while the number of fighters has risen from approximately 32,000 to more than 100,000. In Afghanistan alone, there are as many as 20 such groups operating. And though no one is suggesting that American intervention is the only important factor, it seems more likely that America’s presence in Afghanistan is making things worse than making things better when it comes to eliminating the threat.

Finally, American military and political leaders wrongly believe that the key to “victory” in Afghanistan is merely a question of convincing the Taliban of American resolve. In contrast to Obama, Trump promised that the American presence in Afghanistan would be condition-based, not time limited, in an effort to pressure the Taliban to negotiate. As a Pentagon report from December 2017 put it, “The objective of the campaign is to convince the Taliban that they cannot win on the battlefield.”

With fewer troops on the ground than during the Obama surge, the notion that Trump’s approach is going to produce more leverage is fantastical. Today the Taliban control, contest, or influence more territory than at any point since they were ejected from power in 2001. Making things even worse, the current Afghan government is a disaster. Not only is the government incapable of protecting its own people without help from the United States, Freedom House assesses Afghans as “not free,” the same rating from the Taliban days, and in terms of corruption, Afghanistan ranks fourth worst in the global system. Simply put, nothing the United States is doing will encourage the Taliban to change its course, regardless of how much resolve Trump and his generals have.

The failures of America’s war on terror are obvious at this point — even to the president. During his August 2017 speech, Trump began by noting that he shared the public’s frustration with the costly and prolonged stalemate and that his first instinct was to pull American troops out of Afghanistan. As we remember the victims of 9/11 and honor the millions who have served in the war that followed, it is past time for the United States to find its way out of Afghanistan.