Afghanistan’s struggling government in Kabul will face a serious challenge this summer as a resurgent Taliban under a new and confident leader will launch a major spring and summer offensive. Preparing for what is expected to be a grim summer is one reason US Secretary of State John Kerry visited Kabul to reassure the fragile national unity government of US support.

Nato officials estimate that government forces have full control over no more than 70 per cent of the country, and the resurgent Taliban are stronger than at any time since they were toppled from power in late 2001. The new Taliban leader Mullah Akhtar Mansour has no interest in any peace talks, and has consolidated his authority over the many factions of the Taliban as he speaks of “decisive” battles in its imminent offensive. Mansour’s succession to the former leader Mullah Omar was challenged by many senior Taliban leaders, but he has spent the winter winning over most of the opposition to his leadership.

Kerry helped broker the deal between President Ashraf Gani and Chief Executive Abdullah Abdullah when they formed the current government after a disputed election, but the government has not had much clear direction as it has been weakened by infighting between the rivals as the economy continues to sink, crippled by the enduring political instability and endemic corruption.

What emerged from Kerry’s visit was that the unity government does not have to disband in September when its first two years are up. This makes sense as Afghanistan would be hard pressed to carry out a major constitutional review under a caretaker government, and fight off a major offensive at the same time.