The Taliban is advancing in Afghanistan, launching major offensives to retake key cities as the last remaining US and international forces prepare to pull out. The group has taken more territory in the past couple of months than it has at any time since being ousted from power in 2001. Tens of thousands of Taliban fighters have been killed during twenty years of fighting, yet the militants remain a potent threat to the survival of the Afghan government, its military, and other institutions nurtured by global powers. So what’s the secret behind the Taliban’s longevity? The UN says the sale of opium and illegal mining provides them with a steady stream of income, as do local taxes. Officials in Kabul also allege that the organisation is being propped up by foreign governments and that it continues to welcome foreign fighters in its ranks. Global efforts to starve them of funds have failed and Taliban officials now openly speak of victory, insisting that the United States has ‘lost’. Who’s helping to prop up the Taliban and what does the last two decades tell us about their strength and potential after the last Western forces have gone?

Ritula Shah is joined a panel of Afghanistan experts. Producers: Junaid Ahmed and Paul Schuster.