In what the US military described as a “complex attack,” several terrorists attacked a screening checkpoint at a gate into the Kabul airport and a nearby hotel on Thursday, inflicting a horrific toll of death and destruction.

Unnamed Afghan health officials told the media that at least 60 Afghan citizens were killed and another 140 wounded. The Pentagon said that 12 US Marines were killed and 15 wounded. Many of the wounded civilians and soldiers were in critical condition and the death toll could rise significantly.

At least two suicide bombers were believed to have detonated explosive-laden vests while awaiting or actually undergoing screening by US Marines at the Abbey Gate to the airport. Another suicide bomber, or perhaps a car bomb, exploded outside the Baron Hotel about 100 yards away. At the same time, gunmen opened fire on the crowd assembled outside the gate seeking to gain admittance to the airport and board evacuation flights.

US soldiers opened fire after the bombs were detonated, in order to clear the area in front of the gate. It was not clear whether any of the casualties were the result of that gunfire.

A group calling itself Islamic State-Khorasan, or ISIS-K, released a statement claiming responsibility for the attack. Allegedly a regional branch of ISIS, the group takes its title from the ancient name for the region of Central Asia of which Afghanistan is part.

The Taliban, which the Biden administration calls a “bitter enemy” of the Islamic State, denounced the attack. “The Islamic Emirate strongly condemns the bombing of civilians at Kabul airport, which took place in an area where US forces are responsible for security,” Taliban spokesman Suhail Shaheen said on Twitter.

A Taliban official told the Washington Post that the group has “launched an investigation to know the nature of the blasts and why it happened.”

The day before the attack, the US Embassy in Kabul, which has relocated to the airport, issued an official warning to Americans to stay away from the airport unless they had a scheduled flight to board, and calling on any US citizens near the airport gates to “leave immediately,” citing the imminent danger of a terrorist attack.

The 12 Marines were the first deaths among US troops in Afghanistan since February 2020, after the Trump administration signed a peace deal with the Taliban in which the Islamic group agreed to halt attacks on US forces in return for a commitment that US troops would be withdrawn by May 1, 2021.

President Biden has repeatedly cited that agreement as compelling him to choose between completing the pullout or tearing up the deal and resuming a full-scale war in Afghanistan.

This pullout was largely completed by late July, with a formal handover of Bagram airbase and other US facilities to the Afghan government, but the regime collapsed in the face of a Taliban offensive that culminated in the fall of Kabul on August 15. US troops were then rushed back into the country, using the Kabul airport as a point of entry and as a collection point for evacuations.

The bloodbath at the airport caused political shock waves throughout official Washington. Only 15 minutes before Biden was to meet with Naftali Bennett, the new prime minister of Israel, the White House announced the meeting had been delayed until Friday, and a series of other meetings were canceled as top US national security officials dealt with the crisis.

Biden finally appeared before television cameras at 5 p.m. Washington time. He denounced the attack and said that evacuation flights would continue undeterred. Just over 100,000 people have left Afghanistan since the flights began August 14, and 7,000 more flew out of the airport on Thursday, he said.

Biden rejected calls from Republican congressmen that he drop the August 31 deadline for the removal of US troops, or that he send more troops to the airport and expand their scope of operations, either into Kabul or to seize Bagram airbase, the huge complex north of the capital city that was long the US military headquarters in Afghanistan.

He defended a policy of relying on the Taliban forces to provide security outside the US perimeter at the airfield, saying that there was no alternative, and that the Taliban and ISIS had a long history of conflict. He threatened military action against ISIS, declaring, “We will respond with force and precision at our time, at the place we choose and the moment of our choosing.”

At an earlier press briefing, General Frank McKenzie, head of the US Central Command and in overall command of operations at the Kabul airport, said that terrorist attacks were expected in the remaining four days before all US forces are to be pulled out August 31.

He elaborated on the US military’s de facto alliance with the Taliban, saying US commanders were in regular contact with Islamic group, which was “actually providing the outer security of the airfield … and we will coordinate with them as they go forward.”

He said the face-to-face searches at the three gates to the airport were essential for the security of the airfield and especially of airplanes carrying out the evacuation flights. “You don’t want to let somebody on an airplane carrying a bomb, that could result in massive loss of life if an airplane were to get hit,” he explained.

Other dangers at the airport included rocket attacks, he said, noting that the US military forces “have pretty good protection against that, we have anti-rocket gun systems that have been out there, they are effective against—we feel we would be in good shape for that kind of attack to occur.”

Asked directly—by a reporter for the right-wing Wall Street Journal —whether the Taliban had allowed the bomber to go through to the US checkpoint, McKenzie replied flatly, “I don’t think there is anything to convince me that they let it happen.”

He also indicated that the evacuation flights would begin to include American troops as well and American and Afghan civilians, so that the August 31 withdrawal date would be met. The military planning was complex because it was “designed to maximize evacuees even as we begin to draw down the force on the ground. We recognize there is a need to balance the two.”

In a comment which underscored the precarious character of the US deployment at the airport, McKenzie said US military intelligence was focused on “any sign of something that might pose a threat to aircraft” because “aircraft is the only way we are going to get out of there.”

While the American media uncritically parrots the official claims that the attack was carried out by ISIS-K, the actual circumstances of the bombings are extremely murky. ISIS-K allegedly emerged in Afghanistan over the past few years as an avowed enemy of the Taliban, carrying out attacks that actually benefited the US-backed puppet government.

ISIS itself, initially a split-off from Al Qaeda, received assistance from US allies Saudi Arabia and Qatar to fight against the Syrian government of Bashar al-Assad, before it came into conflict with the US military after crossing the Iraq-Syria border and threatening the US-installed regime in Baghdad.

All of the Islamic fundamentalist terrorist and militia organizations have their origins in the US-backed guerrilla war in Afghanistan from 1979 to 1987, directed against the Soviet-backed government in Kabul. That is where Osama bin Laden formed Al Qaeda, and, after the Soviet pullout, where the Taliban originated, backed by US ally Pakistan.

Because of these deep-rooted connections and switching alliances, it is impossible to say definitely who are the actual perpetrators of Thursday’s bombing and who are their paymasters and masterminds. But the atrocity is one more contribution to the geyser of blood and suffering produced by American imperialism in an oppressed country torn by war and foreign intervention for more than 40 years.