THE world's most powerful military alliance is increasingly vulnerable to attack by unconventional weapons and cyber warfare in particular, Nato governments were warned on Monday.

“The next significant attack on the alliance may well come down a fibre optic cable,” according to a draft new Nato “strategic concept”. There are unacceptable, “serious gaps” in Nato's cyber defences, it says.

The warnings are contained in a report by a group of experts chaired by Madeleine Albright, the former US secretary of state. They will provide the basis for an agreement due to be signed by Nato leaders at a summit in Lisbon in November.

Senior Nato military officials say they are concerned about the lack of coordinated planning against cyber attacks. They are wrestling with the prospect of member states asking for help under Article 5 of the Nato treaty, originally designed to provide mutual assistance to an ally faced with a conventional military attack.

Asked whether a cyber attack or the cutting off of energy supplies — also cited in the report — would in future be considered a military attack, the paper dodges the issue by stating that whether Nato's article five would be triggered would depend on “the nature, source, scope, and other aspects of the particular security challenge”. Article 5 was invoked for the first, and so far only, time after 9/11. Three years ago, Estonia appealed to its Nato and EU partners for help against cyber attacks it linked to Russia.

— The Guardian, London