22 May Washington Post commentary - For Estonia and NATO, A New Kind of War by Anne Applebaum.

And now for a quick quiz: A European country -- a member in good standing of NATO and the European Union -- has recently suffered multiple attacks on its institutions. Can you (a) name the country, (b) describe the attacks and (c) explain what NATO is doing in response?

If you can't, don't worry: NATO itself doesn't quite know what it is doing about the attacks, despite the alliance's treaty, which declares that an armed attack on one of its members is "an attack against them all." The country is Estonia -- a very small, very recent member of NATO; the attacks are taking place in cyberspace; and while the perpetrators aren't exactly unknown, their identities can't be proved either...