"Some in the UK believe the fight is not worth it"

The Defence Secretary says that opposing war in Afghanistan is "defeatism"

When I was in Afghanistan at the start of Operation Panther's Claw, one officer told me how his soldiers explained to their families what they were doing in that country - "We are here to help the Afghan people and to protect national security," he said. I was struck by his words. These are the men and women who are doing the hard yards. Some have paid the ultimate price. They know they are in Afghanistan to prevent the country becoming a haven for terrorists, as it was in 2001. But they are also motivated by the plight of the people they are fighting alongside. They understand clearly why they are there and the progress they are making.

This sense of purpose and momentum has not translated to the home front in the way that it might have. Despite the huge influx of US and other Nato troops, despite the focus of the Obama administration and the recent success of operations in Helmand, some in the UK believe the fight is not worth it. This defeatism has been exacerbated by political arguments about British troop levels, vehicles and helicopters that often misunderstand the nature of coalition warfare.

The war in Afghanistan is too important to be reduced to a political football. We are fighting there to protect our national security. We are confronting the Taliban-led insurgency to prevent terrorists returning to that country. We are operating as part of a 42-nation coalition because this is about international security, too. We cannot allow Afghanistan to become again a haven for terrorists who inspire, plan and provide support for attacks like those of 11 September 2001, of 7 July 2005 in London, and more.

The reasoning for our civil-military plan is that lasting success will be when the Afghan government, security forces and people can resist the insurgents and terrorists themselves. We are not in Afghanistan because girls were not allowed to go to school, but helping them do so will give the Afghan people hope for a better future. Building governance and services brings faith in the government and reconfirms that the coalition is operating as a force for good - not as an occupier or an invader.

Some ask: how can you claim to be protecting Britain from terrorism when al-Qaeda is now in Pakistan, not Afghanistan? We are in Afghanistan because the Afghan security forces are not able to tackle al-Qaeda and other terrorist groups on their own. But working with Pakistan to reduce the threat is imperative for success. We recognise the heavy sacrifices that the Pakistani security forces are making in taking on violent extremists within their borders, and the humanitarian cost the people of Pakistan are bearing. Together we are achieving some success. The Taliban, terrorists and violent extremists are being squeezed from both sides. But we must keep up the pressure. This is a tough fight and it is a long way from over. Our armed forces are doing their job courageously and with great skill. They deserve our support to see it through.

Bob Ainsworth is Secretary of State for Defence