Dinara Safina was forced to withdraw from the season-ending Sony Ericsson Championships in Doha with a back injury last night, leaving Serena Williams to end 2009 as the world's number one - a feat the American celebrated with a defeat of her sister Venus.

Nato defence ministers were today expected to approve an extension of the alliance’s Afghan security mission across the whole of the country, taking in the volatile eastern region and bringing around 10,000 US troops under allied command.

Nato’s battle with the Taliban in southern Afghanistan and a possible extension of the alliance’s support for African peacekeepers in Darfur are set to dominate a meeting of allied defence ministers this week on Slovenia’s Adriatic coast.