Five years ago to the day, the Taliban swept out of the mountains, villages and fields and retook Kabul.

After twenty years of war, the vast Western coalition assembled to fight them fled ignominiously, leaving behind billions of dollars' worth of infrastructure and military hardware, much of it supplied by the Americans to the Afghan forces.

Today is 'Freedom Day', the Taliban (the word means 'students' in Pashto, one of the country's two official languages) are celebrating – and that hardware is all around me.

American-made helicopters fly overhead in the early morning. Taliban soldiers stand guard holding American M16 rifles. Armoured Ford 4x4s drive past with Taliban hanging from the sides. They zoom past on motorcycles.

Everywhere you look is the white flag of the Islamic Emirate filled with black Arabic calligraphy across the centre spelling out the shahada, the Islamic declaration of faith: (Lā ilāha illā Allāh, Muḥammadun rasūlu Allāh) 'There is no god but God; Muhammad is the Messenger of God.'