From Radio Free Europe / Radio Liberty: "The latest row stems from the spying conviction in Tallinn in February of a former top Estonian defense official, Herman Simm. Simm was the man who handled all Estonia’s top-secret material from NATO. He was found guilty of spying for Russian intelligence and sentenced to 12 1/2 years in prison.

Western intelligence officials describe the case as the most serious security leak involving NATO since the end of the end of the Cold War."