The so-called rules of engagement will “provide a defined framework for how best to respond to the plethora of cyber-threats we face,” said Lt. Col. Damien Pickart, a Pentagon spokesman.

The rules will be secret and cover more conventional combat as well.

The cyber-warfare rules are the most contentious because it is a new domain.

“The technologies and capabilities are developing so rapidly that sometimes policies have to catch up,” said Terry Roberts, a vice president at TASC, an engineering services company that works with the intelligence community and the Defense Department.

The Pentagon said the military has existing rules that allow it to defend the nation, but analysts say the new rules will give military commanders clearer guidance and make it easier to take action without clearing it at the presidential level.