Editor's Note: (Peter Bergen is CNN's national security analyst, a vice president at New America and a professor of practice at Arizona State University. He has reported from Afghanistan since 1993.The views expressed in this commentary belong solely to the author. View more opinion at CNN. )
(CNN) President Biden's decision to announce a date for pulling all US troops out of Afghanistan by the 20th anniversary of 9/11 sets the stage for a predictable disaster.
The absence of American troops doesn't equal peace, although, in the minds of many on both the left (the Biden administration) and the right (former President Donald Trump), the withdrawal of US soldiers is seen as a way to "end the war." A tour through history shows the fallacy in this thinking.
The United States has made this kind of blunder before, with disastrous consequences. In Afghanistan, in the 1990s. After occupying the country for a decade, the Soviet Union pulled out of the country in early 1989. The CIA officer responsible then for arming the Afghan resistance against the Soviets sent a cable to headquarters saying simply, "WE WON."
As the Soviets withdrew, the US closed its embassy in Afghanistan, abandoning the country.
The US was largely "blind" in Afghanistan during the years of civil war that followed. That led to the emergence of the Taliban, which then gave sanctuary to al Qaeda. Al Qaeda, of course, planned the 9/11 attacks from its base in Afghanistan and trained its hijackers there.
After 9/11, the United States then had to invade Afghanistan to topple the Taliban and remove al Qaeda from the country.
A similar dynamic played out a decade later when then-Vice President Joe Biden and his then-national security adviser, Tony Blinken, negotiated the pullout of all American troops from Iraq in December 2011. A headline from Reuters nicely captured the hubris of the moment: "Last U.S. troops leave Iraq, ending war."
Of course, the war didn't end after the US withdrawal, it got much worse.
Three years later, ISIS took over much of the country, including Mosul, the second-largest Iraqi city. The group also seized large sections of neighboring Syria.
In its safe haven, ISIS then trained terrorists for large-scale attacks in Western cities, such as Paris, where ISIS claimed credit for killing 130 people in coordinated attacks in November 2015. The group also inspired attacks in American cities such as Orlando, where 49 people were killed by an ISIS-inspired terrorist in 2016.
The US then had to send thousands of troops back into Iraq to destroy the ISIS regime, a process that took three-and-a-half years.
There has to be some magical thinking going on for the Biden White House to expect that there will be a different outcome in Afghanistan. Yes, al Qaeda is a mere shadow of what it was on 9/11. That's because for the past two decades, the US and its allies have prevented Afghanistan from becoming a safe haven for al Qaeda and allied groups. It's a policy that has worked.
Now, that sound policy is being abandoned. Once the US leaves Afghanistan, America's NATO allies, who have 7,000 soldiers on the ground, will leave as well, since they rely on an American security umbrella. President Biden confirmed this in his speech to the nation Wednesday afternoon.
The pullout of US and NATO troops will likely enable the Taliban to take over much of the country.
Despite much wishful thinking that the Taliban won't host al Qaeda and other jihadist groups as they did before 9/11, according to a report by the United Nations released last year, "the Taliban regularly consulted" with al Qaeda during its recent peace negotiations with the United States, while guaranteeing that they "would honor their historical ties" with the terrorist group.
The UN also assessed that the links between al Qaeda and the Taliban "have remained strong" and "have been continually reinforced by pledges of allegiance" by al Qaeda's leaders to the leader of the Taliban.
And then there is also the small matter of ISIS, which maintains a foothold in Afghanistan.
Of course, US policy failures in Afghanistan didn't begin with Biden. Trump often called for a total US withdrawal from the country, undermining the elected Afghan government and emboldening the Taliban, with predictable consequences.
Right now, the US is abandoning Afghanistan for no discernible reason. The small footprint of no more than 3,500 US troops in Afghanistan has meant that for more than a year no American soldiers have been killed there. (By contrast, there were 56 deaths of US Army soldiers overall caused by accidents in the most recent fiscal year.)
It's worth recalling, too, that South Korea was one of the poorest countries in the world at the end of the Korean War in 1953.
Seven decades later, under an American security umbrella that includes more than 28,000 US troops posted there today, it has become one of the richest countries in the world. And during much of that period of growth, South Korea was an authoritarian state, not the democracy it is today.
Afghanistan isn't South Korea, of course, but change in both countries did happen, albeit slowly and unevenly. Even a senior Biden administration official in a background briefing about Afghanistan with reporters Tuesday conceded that "a lot has changed in two decades. In 2001, there were fewer than nine hundred thousand children, almost all boys, in school. Today, there's over 9.2 million children, forty percent of which are girls, in school. Life expectancy has gone from 44 years to 60 years."
Which raises the question: What PR genius in the Biden administration thought that a good way to memorialize the 20th anniversary of 9/11 was to abandon the country where the plot was incubated?
On September 11, it's going to be a tragic split-screen to watch the Taliban celebrate their "defeat" of the American superpower, while the victims of 9/11 are memorialized in downtown Manhattan.