President Trump’s secret plan to meet the Taliban at Camp David, to negotiate the withdrawal of American forces from Afghanistan, shows his misunderstanding of our enemy’s character and dangers they pose to the United States.

I was an Army veteran and junior associate at a Wall Street law firm on Sept. 11, 2001. Like most New Yorkers, I lost friends that day. Fortunately, I held a reserve commission, so I could simply volunteer for duty, and I did so on Sept. 12. I served twice, briefly, in Afghanistan, although I never fired a shot in anger.

No veteran should purport to represent the views of all who served, and none ought to presume to speak for the fallen. Yet Saturday’s news gave me, and many Americans of all backgrounds, pause at how confused we have become.

It is not wrong to pursue peace with enemies; American diplomats coolly negotiated with communists from North Korea and North Vietnam in Panmunjom and Paris. But for Trump to invite the Taliban to Camp David was a mistake — as if Neville Chamberlain had invited Adolf Hitler to Chequers.

Any veteran can tell you about the Taliban’s depravity. Around the time of my second tour, the Taliban bombed a nearby girls' school, disfiguring its students by throwing acid in their faces; they wired a baby donkey with explosives to lure the children of a local police official from their home and kill them; elsewhere, they attacked new mothers, their babies, and staff at a maternity clinic.

These are not traditional military enemies. To invite such people to the weekend family home of presidents since Franklin Roosevelt, in an admitted attempt to obtain a political goal before an upcoming domestic election, is just a bad idea — in poor taste, to put it mildly.

Taliban leaders had foreknowledge of, facilitated, and bear responsibility for the attacks of Sept. 11, 2001. A new generation understandably holds no memory of that day. Inexcusably, some policymakers have apparently forgotten its lessons: the 2,977 murdered that day, the civilians trapped on hijacked planes and in the towers, and the first responders who have since died from 9/11-related diseases.

And it was nearly much worse. If not for a flight delay in Boston, both Flight 175 and Flight 11 would have hit both towers simultaneously, causing much greater loss of life without time for the evacuations that occurred. Mercifully, Flight 77 hit a reinforced portion of the Pentagon and disintegrated instead of slicing through the building. And valiant passengers kept Flight 93 from crashing into a joint session of Congress.

Before 9/11, al Qaeda plots hatched under Taliban protection included bombing U.S. embassies in East Africa in 1998, killing 224, a failed attack against Los Angeles International Airport, an attempt on the USS The Sullivans, and a strike on the USS Cole in 2000, killing 17.

Before 9/11, further plots were launched and operatives dispatched from Afghanistan. Jose Padilla planned a radiological “dirty bomb” attack to destroy Manhattan apartment buildings, before his arrest by the FBI. The New York Police Department deterred Khalid Sheikh Muhammad’s attack on the Brooklyn Bridge. A second wave of airliners was to crash into West Coast buildings, such as California’s Library Tower, before the CIA seized that scheme’s ringleader.

Even after we chased al Qaeda and the Taliban across into Pakistan in fall 2001, for a decade they still plotted attacks on airliners flying from Britain to America, New Jersey commuter trains, New York City subways, and the Long Island railroad. We also know of an attempt, specific to the Pakistani Taliban, to car-bomb Times Square in 2010.

Al Qaeda leader Osama bin Laden was killed in 2011, and Taliban leader Mullah Omar died after that, but their 9/11-era deputies survive. Al Qaeda’s intrinsic determination to attack the U.S., and the Taliban’s sympathetic willingness to harbor them, have not changed one bit.

The Taliban will not consider itself bound by agreements with Western governments, nor with what they consider an apostate Muslim regime in Kabul. Most Afghan officials are corrupt, and Afghan military and police losses are now so bad that they are classified. The Taliban will make quick work of the flawed Kabul government without minimal U.S. military training, advice, and assistance including air, logistics, and medical support.

The Taliban and al Qaeda will then be stronger than ever, correctly perceived by the Islamic world as having outlasted and outwitted America in battle, even after they together perpetrated mass-casualty attacks on the military headquarters in our capital and civilians in our largest city.

Together they will put those who supported the U.S. to the sword (as the Vietnamese did to our allies in Southeast Asia in 1975), subjugate women whose liberation we encouraged, and enslave religious and ethnic minorities such as Shiites and Hazaras.

Then, protected by the Taliban, al Qaeda will again turn its sights on targets in our homeland.

In Parliament after the 1938 Munich summit, when Czechoslovakia was delivered up to the Nazis, Winston Churchill presciently warned the appeasers, “You were given the choice between war and dishonor. You chose dishonor, and you will have war.”

This was nearly the epitaph of the Trump administration in Afghanistan: shameful surrender to the Taliban, followed by al Qaeda attacks on the U.S.

Instead, let us remember those who died because of the Taliban, attacks at home narrowly averted over the following decade, and the irredeemable evil of the enemies we face. Let us recommit the administration, Congress, and the public to staying the course in Afghanistan.

Kevin Carroll was a senior counselor to former Homeland Security Secretary John Kelly. He earlier served in Afghanistan as the Joint Staff Directorate of Intelligence’s liaison to the XVIII Airborne Corps Leadership Targeting Cell in Bagram in 2003 and as a military case officer augmented to the 75th Ranger Regiment in Kandahar in 2010.