Leading article: Rethinking the Afghan war

The US President's special envoy, the energetic and outspoken Richard Holbrooke, arrived in Kabul yesterday from Pakistan on the latest leg of his fact-finding mission to the region. From what he has already said about the spreading chaos in Afghanistan, Mr Holbrooke is under no illusions about the scale of the task ahead. The bomb attacks on public buildings, including the Justice Ministry, the day before his arrival showed the ease with which the Taliban can now move around, even in the capital. Bringing security to the country looks ever harder.

Barack Obama has made Afghanistan a centrepiece of his foreign and defence policy. He has long been adamant that in invading Iraq, President Bush chose to fight the wrong war. As he reduces the US presence in Iraq, he intends to return the military and diplomatic focus to Afghanistan. The stated goal is the same as it was at the start: to prevent the country from ever again becoming a haven for terrorists. Such an objective was never going to be simple. But it is considerably more complex now than it was. Seven-and-a-half years ago the Taliban were on the run; the international force was designed to have a facilitating and rebuilding role. For a while there was hope and a common sense of purpose.

All that has gone. The security situation in Afghanistan has deteriorated markedly in the past six months. A majority of provinces have slipped out of Kabul's control; foreign troops have become the enemy, and the Taliban have infiltrated ever closer to Kabul. In one of his first acts as President, Mr Obama announced a 60-day review of policy towards Afghanistan; Mr Holbrooke's trip is part of it.

Several assumptions have been made about future US tactics; they include an Iraq-style "surge", necessitating a sharp increase in troop numbers and a tighter central command. But the US has made clear that all options – except defeat – are on the table. This is the time for Britain, and the other European allies, to state what they believe is feasible and how they would be prepared to contribute. This is an opportunity to help shape what comes next; we should take it in the serious spirit it has been offered.