A well-thumbed copy of Not a Good Day to Die, which tells how American forces nearly came undone fighting in Afghanistan in the early stages of the war, lies on a bed in a deserted United States barrack room at Kabul airport.

On a table next to it are two water bottles, a couple of empty bullet casings and a smoke grenade. A bottle of Tabasco hot sauce – a United States military staple – sits on another.

In a separate room, an overwhelming smell of rotting food pervades as a Taliban fighter armed with an M16 rifle takes pictures on his mobile phone.

A month after the Taliban’s takeover of Afghanistan, signs of the 20-year US-led occupation are still visible at Kabul’s airport, including clear evidence of Washington’s humiliating exit.

US medical kits, vests, shoes, mattresses, toilet paper, documents and other items are scattered about the military quarters of the airport, not yet disposed of by the new rulers of the devastated country.

“The Taliban takeover was unimaginable … but the US exit was truly unthinkable,” said an Afghan security guard who had a front-row seat of the withdrawal operation from the civilian side of the airport.

The panic and confusion as the Taliban entered the capital was plain to see, he said.

“It was the first time I saw US soldiers like this.”

The state of what has been left behind bears testimony to the panicked exit.

In a field clinic at the US camp, next to a small fire station, first aid kits are hung on sandbags a few metres from an outdoor gym, a volleyball court and a meeting room with red chairs that resembles an indoor cinema.

A strong smell of disinfectant rises from the rooms, where boxes of medical equipment are still untouched and folding beds covered in grey sheets are left open.

In part of the military side of the airport this week, dozens of damaged planes and vehicles were cordoned off by Taliban barricades made of anything from umbrellas to folding metal chairs.

Abandoned Afghan military uniforms litter the floors of hangars filled with bullet-riddled helicopters.

Standing next to a small plane with no doors, a Taliban fighter looks at shattered windows and says loudly with a smile: “Boom, boom, boom.”