The departure of the last U.S. military plane from Afghanistan left the region facing uncertainty, with the Taliban seeking to cement control of a nation shattered by two decades of war and an economy long dependent on foreign aid and opium sales.

Now the U.S., its allies and adversaries including Russia and China must all regroup and assess how they’ll approach the Taliban, which swept to power with stunning speed as American and NATO troops withdrew over the summer. The chaos of the American withdrawal following the collapse of Ashraf Ghani’s government only underscores the country’s fragility and the daunting challenges that await.

After evacuating some 120,000 people, the U.S. says it will look to help any Americans who remain in the country. Less certain is the fate of the tens of thousands of Afghans — civil society workers, women and girls, minorities — who may still want to flee but couldn’t make it through the crush of people at Kabul’s airport this month.