"Afghanistan was the ultimate nation building mission ... and we had a moral obligation to leave behind something better," wrote former US President George W. Bush in his memoir, introspecting on the motives for ordering the invasion of Afghanistan in 2001.

As the United States pulls out, 20 years of what Washington called "nation building" is crumbling before the eyes of the world. And death, bloodshed and a tremendous humanitarian tragedy are what the United States has truly left behind in Afghanistan, which is vividly exemplified by some Afghans who fell to death from a US military plane rushing to leave.

Since entering Afghanistan, US troops have caused more than 30,000 civilian deaths, injured more than 60,000 and turned 11 million people into refugees.

According to official figures, just in 2019, at least 6,825 drone strikes took place in Afghanistan, and 7,423 bombs and other munitions were dropped on the land, an average of 20 bombs a day. With US bombs blasting all around, peace and stability have long been a goal far beyond the reach of ordinary Afghans.

The 20-year-long US war in Afghanistan abounds with heartrending tragedies of ordinary Afghan families. One of them was a deadly US airstrike on an Afghan hospital run by Doctors Without Borders (MSF) in 2015. Though around 40 civilians were killed in what the MSF called "a war crime," the Pentagon downplayed the severity of its felony by claiming that the deadly attack was "caused primarily by human error."

On March 5, 2020, the Appeals Chamber of the International Criminal Court (ICC) ruled that its prosecutor could open an investigation into war crimes and crimes against humanity in the Afghan war since May 2003, including those committed by members of the US armed forces and the CIA (Central Intelligence Agency), such as alleged attacks against hospitals and other non-military targets, civilian casualties by drones, abuse of prisoners and torture.

In a move typical of US hegemony and bullying, Washington then blocked the financial assets of certain ICC staff and imposed visa restrictions on them and their immediate family members as retaliation.

To justify Washington's economic and legal offensive, then US Attorney General William Barr claimed that the measures "are an important first step in holding the ICC accountable for exceeding its mandate and violating the sovereignty of the United States."

The tragic irony is that the United States, a country that least respects the sovereignty of other states, wanted to use sovereignty as a pretext to block an independent investigation by the ICC into its war crimes.

Two decades ago, the United States roared into Afghanistan in the name of fighting terrorism. If they could have limited their focus on the claimed target, the atrocities this Asian nation has suffered from over the decades might not have been that horrifying. And yet Washington's imperial hubris has overwhelmed its rationality, and the Afghan people have paid a monumental price.

"The United States exposed Afghans to prolonged harm in order to defend America from another terrorist attack," Carter Malkasian, a historian who once served as a senior advisor to the US military commander in Afghanistan, wrote in his book The American War in Afghanistan.

The United States may have chosen to leave on its own terms, yet the unspeakable atrocities it has perpetrated against the country and its people will be indelibly imprinted on the mind of people across the world.