WASHINGTON — President Joe Biden has set August 31 as the date for removing all U.S. military forces from Afghanistan after 20 years of America’s longest war. He has done so despite the advances of the TaIiban rebels who hold much of the country, threatening the shaky regime in Kabul.

Biden has pledged continued military aid after turning over to the regime last week the huge Bagram airbase and promising to protect the safety or relocation of the many Afghan nationals who served the Americans as interpreters, a difficult undertaking under the circumstances on the ground.

Biden acted in the wake of a civil war that has claimed the lives of about 2,400 Americans at an additional cost of of trillions of dollars. Those facts have led him to attempt to avert its collapse with a much smaller U.S. footprint in the embattled country.

In defense of his decision, the president posed this question: “So let me ask those who wanted us to stay: How many more — how many thousands more of America’s daughters and sons are you willing to risk? How long would you have them stay? ... I will not send another generation of Americans to war in Afghanistan with no reasonable expectation of achieving a different outcome.”

At the same time, he argued it was “not inevitable” that the country would fall to the Taliban if President Ashraf Ghani’s regime in Kabul would “come together and drive toward a future that the Afghan people want.” But American intelligence officials have warned that it could happen within six months to a year, leaving Biden subject to second-guessers regardless of political affiliation at home.

One fellow Democrat, Sen. Jeanne Shaheen of New Hampshire, offered, “Sadly, this follows a trajectory that I feared: a resurgence of the Taliban and direct threats to communities vulnerable to their violence and oppression.” Republican Sen. Lindsey Graham of South Carolina compared Biden’s Afghan decision to what he called the earlier “Iraq withdrawal” and said it was made counter to “sound military advice.”

But Biden noted regarding Afghanistan: “In 2011, the NATO Allies and partners agreed that we would end our combat mission in 2014. In 2014, some argued, ‘One more year.’ So we kept fighting, and we kept taking casualties. In 2015, the same. And on and on. Nearly 20 years of experience has shown us that the current security situation only confirms that ‘just one more year’ of fighting in Afghanistan is not a solution but a recipe for being there indefinitely.”

He also rejected the criticism that he was heading the country into another Vietnam debacle like 1975, when Americans were obliged to abandon the American embassy in Saigon, calling the Afghan withdrawal “not at all comparable.”

As for concern for the safety of Afghan nationals placed in jeopardy after serving as interpreters for the American forces in their country, he told them: “There is a home for you in the United States if you so choose,” with flights here provided. He also said up to a thousand U.S. troops will remain to guard the American embassy and the airport in Kabul.

But coping with the uncertainty of Afghanistan’s survival will be a distraction for the president as he strives to focus on the COVID-19 pandemic at home and a return to normal government after the four years of chaos under Donald Trump.

Jules Witcover’s latest book is “The American Vice Presidency: From Irrelevance to Power,” published by Smithsonian Books. You can respond to this column at juleswitcover@comcast.net.