“Even war has rules,” said Doctors Without Borders head Dr. Joanne Liu as part of her response to the devastating US bombing of the organization’s hospital in Kunduz, Afghanistan earlier this October.

After a series of different explanations and excuses – four separate accounts of the incident over the first four days, by The Guardian’s count – the United States still hasn’t provided a concrete explanation as to why and how the hospital was targeted, killing 22 doctors and patients. The attack was the worst on any Doctors Without Borders hospital in its 44 years of operating.

But it wasn’t all that different from other recent US attacks on civilian infrastructure. Since as far back as 1991, the US has been “accidentally” blowing up medical and humanitarian facilities in a range of places, resulting in high civilian casualties and other “collateral damage.”

To name but a few, in 1991 the US targeted an air raid shelter in Baghdad, killing 408 Iraqi civilians. (A US general claimed the shelter was “an active command-and-control center.”) In 1998 the Clinton administration attacked the Al Shifa pharmaceutical factory in Sudan, which the US claimed was associated with the bin Laden network and was “involved in the production of materials for chemical weapons.” As a result, according to The Intercept, “tens of thousands of people have suffered and died” from “treatable diseases” in the country since then. In 2001, the US attacked the complex that housed the International Committee of the Red Cross in Kabul – not once but twice, destroying storage warehouses that held food and supplies for refugees.

The incident in Kunduz, unfortunately, just adds to the list.

While past incidents have often failed to elicit serious calls for accountability, Doctors Without Borders – also known by its French name, Médecins Sans Frontières, or MSF – responded with an outraged press release demanding an independent, impartial investigation of the incident. Appalled by the lack of responsibility taken by either the Afghan or US government, MSF characterized the strike as an attack on the Geneva Conventions. “This cannot be tolerated,” the statement explained. “These Conventions govern the rules of war and were established to protect civilians in conflicts – including patients, medical workers, and facilities. They bring some humanity into what is otherwise an inhumane situation.”

So far, the United States is refusing to comply with MSF’s request for an independent, impartial investigation and instead is carrying out three investigations of its own conducted by the Department of Defense.

Any properly independent inquiry will have to accommodate a variety of egregious facts.

The hospital’s GPS coordinates, for instance, were known by both the US and Afghan governments. Even after panicked MSF doctors phoned the authorities amid the strikes to alert them that they were attacking a hospital, the bombing continued for another 30 minutes. The hospital treated victims regardless of their political affiliation or religion, giving lie to any insinuation by the US military or Afghan authorities that the location was friendly to the Taliban or Al Qaeda.

Add to that list: After the attack, a US military tank forced its way into the destroyed hospital. The tank was allegedly carrying US, Afghan, and NATO investigators, but it may have destroyed evidence crucial to the investigation.

Without pressure from the public – including mainstream journalists – the United States won’t have much difficulty ignoring the controversies of this incident. That’s why MSF itself is rallying supporters to keep up the pressure for an independent investigation. The group’s website currently features a sign-on petition calling on the Obama administration to allow “a truly impartial truth-seeking investigation.”

Since the attack, Pentagon Press Secretary Peter Cook has made clear the US will “work with those affected to determine appropriate payments,” but still hasn’t agreed to an independent, impartial investigation. Meanwhile, with the MSF hospital in Kunduz out of service, there’s no center anywhere in the region that can provide emergency medical attention for victims of the conflict.

In a grim addendum, the Obama administration recently announced that 9,800 US troops will remain in Afghanistan for another year because “Afghan forces are still not as strong as they need to be… and in some places there is risk of deterioration.”

Oh the irony.

Nazish Kolsy is a contributor to Foreign Policy In Focus. Reprinted with permission from Foreign Policy In Focus.