Nato defence ministers will today hold their first in-depth discussion on how the 26-member alliance should respond militarily to Russia's new challenge to the west following its recent conflict with Georgia.

Over the last decade, Nato's central focus has been on meeting challenges outside the alliance's home territory, above all confronting the Taliban in Afghanistan. But at a summit in London today and tomorrow, defence ministers will start questioning whether Nato needs a strategic rethink, putting more focus on the organisation's traditional commitment to defend European members from attack.