When Russian soldiers crossed the border to fight with rebels in Ukraine earlier this year, Moscow said they had not been deployed but had gone on their own vacation time.
When Estonia was the victim of a cyberattack in 2007 and blamed Moscow, the Kremlin responded that it could not control patriotic Russian hackers.
Western strategists who built their defenses to counter a massive invasion, nuclear missiles or terrorism are still trying to work out how to cope with this sort of threat that disrupts and destabilizes from behind a mask of deniability.