Updated

The U.S. service academies are ramping up efforts to groom a new breed of cyberspace warriors to confront increasing threats to the nation's critical computer networks.

Students at the Army, Navy and Air Force academies are taking more courses and competing in elaborate cyberwarfare exercises as they learn the theory and practice of computer warfare.

The academies have been training cadets in cyber for more than a decade. But the effort has taken on new urgency amid warnings that hostile nations or organizations might be capable of crippling attacks on critical networks.

James Clapper, director of national intelligence, says cyberattacks are the top threat to national security.

Cyber was once viewed as an obscure pursuit, but now it's considered one of the hottest fields in warfare.