Cyberwarfare is the use or targeting in a battlespace or warfare context of computers, online control systems and networks. It involves both offensive and defensive operations pertaining to the threat of cyberattacks, espionage and sabotage. There has been controversy over whether such operations can be called "war". Nevertheless, powers have been developing cyber capabilities and engaged in cyberwarfare, both offensively and defensively, including the United States, China, Russia, Israel and the United Kingdom. Two other notable players are Iran and North Korea.