A Global Ban on Robot Warriors?

Should autonomous weapons systems be permitted on the battlefield in the absence of a clear sense of how fully they can comply with the laws of war?

Noel Sharkey, a robotics expert at University of Sheffield in the UK, thinks not. In an article entitled "Killer Robots: Friend or Foe," MSNBC'S Alan Boyle writes:

"Nowadays, Sharkey is sounding the alarm about the prospect of real-life robot wars: He's calling for an international ban on autonomous weapon systems until it can be shown that they can obey the laws of war. 'I think we should be addressing this immediately,' Sharkey told me. 'I think we've already stepped over the line.'"

The precautionary principle, popularized in the environmental policy-making arena, suggests that the burden should be on policymakers to demonstrate the safety of a new product or technology, rather than on citizens to demonstrate its harmfulness.

So maybe Sharkey has a point. Should the use of lethal robots on the battlefield be the subject of a multi-lateral treatymaking process? What threshhold might we envision determining whether such autonomous sytems constituted a lawful alternative to organic warriors?