Britain is not close to an exit strategy in Afghanistan, Armed Forces Minister Adam Ingram has told MPs.
Royal Marines are protecting engineers at a new Afghan base
Mr Ingram told the Commons defence committee that security capacity had to be built up in any country of conflict before there could be an exit strategy.
The Taleban would not necessarily return to power if British and other troops left Afghanistan, he said.
But "bad elements" could emerge, setting up terrorist training grounds, and developing the narcotics trade.
They could grow "the capability to attack us", he warned.
Mr Ingram said nobody wanted a repeat of the terror attacks seen on 11 September 2001, which prompted the invasion of Afghanistan.
But the international community and the Afghan government faced a range of attitudes and people who would not go away, he argued.
The UK last month began an enlarged deployment to Afghanistan, sending an extra 3,300 troops to focus on reconstruction, rather than counter-terrorism.
Mr Ingram the international community needed to create confidence in Afghan society to persuade people to go down the democratic route.
He admitted that this would not happen overnight even with the massive resources that had been put in.