The Pentagon's new Cyber Command is seeking authority to attack computer networks around the globe to protect American interests, drawing objections from Obama administration lawyers uncertain about the legality of offensive operations.

Cyber Command's commander, General Keith Alexander, who also heads the National Security Agency, wants his new command to be able to mount what he has called ''the full spectrum'' of operations in cyberspace.

Offensive actions could include shutting down part of an opponent's computer network or changing a line of code in an adversary's computer. They are operations that destroy, disrupt or degrade targeted computers or networks.

But current and former officials say that senior policymakers and administration lawyers want to limit the military's offensive computer operations to war zones such as Afghanistan, in part because the CIA claims covert operations outside the battle zone are its responsibility and the State Department is concerned about a diplomatic backlash.

The administration debate is part of a larger effort to develop a coherent strategy to guide the government in defending the US from attacks on computer and information systems that officials say could damage power grids, corrupt financial transactions or disable an internet service provider.