Successive American administrations have not tried to dissuade the Israelis from extensive use of drones to carry out precision strikes on Palestinian fighters, particularly in the Gaza Strip. If China, however, began firing missiles from drones the US would be faced with an awkward dilemma.

The legitimacy of their use remains a matter of fierce dispute. The White House contends that drones — estimated to have killed more than 3,000 people, some 400 of them innocent civilians, since 2008 — are more humane than conventional warfare because fewer civilians are killed.

Their deployment against suspected al-Qaeda members, it argues, is justified by the Authorisation for Use of Military Force Against Terrorists statute passed just after the attacks of September 2001.

Critics are unconvinced. The American Civil Liberties Union argues that the use of lethal force outside conflict zones is strictly limited by international law and, when it comes to American citizens, the US constitution. Lethal force, it insists, can be used only as a last resort when there is an imminent threat to life or against those directly participating in hostilities. If the rules of engagement for drones remain vague, those concerning the development and deployment of cyberweapons are even less defined.

What is an act of war in cyberspace? Where are the lines that cannot be crossed? No one really knows.

Last summer, an attack believed by western intelligence services to have been carried out by Iran destroyed 30,000 computers owned by Saudi Aramco, the Saudi government-owned oil company. The malware replaced data with an image of a burning American flag. Russia has been blamed for cyberattacks against Estonia and Georgia.

“We spent 20 years pulling the whole world together in one network, one global economy and now we’re finding out that that brings vulnerability as well as benefits,” says Thomas Wright, a fellow at the Brookings Institution think tank in Washington.

“It’s the darker side of integration. It’s also the new normal because there’s no way to undo it. Obama really needs to outline a doctrine for the use of these new technologies because not saying anything is becoming untenable. By pulling back and not engaging in that, there’s a vacuum created that others are going to fill.”