"From the German point of view the conference was a great success," he told journalists after the 70-nation talks on Thursday. "The fact that the Afghan government had set its own goals for its future development and received international backing for them was "important," he said, adding: "Perhaps it is the famous turning point."
Germany, which has 4,300 troops in Afghanistan and has pledged to send a further 500, welcomed the goal agreed by the London conference of passing over control of some provinces to local security forces by the end of the year.
Westerwelle said Berlin wanted to see "full control of responsibility for security handed over to the Afghan government in 2014. That means there is now the prospect of (international forces) pulling out," he said.
The foreign minister said he strongly supported the Afghan government's plan to persuade moderate Taliban to renounce violence in return for jobs and a place in mainstream society.
"Bridges must be built for those who take the weapons for a few hundred dollars," he said, underlining that many Taliban only fight for the insurgency because there is little other employment.
Germany will provide €10 million ($14 million) towards the fund in its first year, out of a total $140 million dollars pledged at the conference.
It would also push Afghanistan to honour pledges to develop its democracy, while keeping an eye out for "fairer treatment of women," Westerwelle added.