“Acts that kill or injure persons or destroy or damage objects are unambiguously uses of force,” according to “The Tallinn Manual on the International Law Applicable to Cyber Warfare.”

Michael D. Schmitt, the manual’s lead author, told The Washington Times that “according to the U.N. charter, the use of force is prohibited, except in self-defense.”

Under the charter, states may use force in self-defense — and that, some argue, includes “anticipatory self-defense” against an incipient or imminent attack.

The international group of researchers who wrote the manual were unanimous that Stuxnet — the self-replicating cyberweapon that destroyed Iranian centrifuges that were enriching uranium — was an act of force, said Mr. Schmitt, professor of international law at the U.S. Naval War College in Newport, R.I.

But they were divided on whether its effects were severe enough to constitute an “armed attack,” he said.