LASER-guided robotic machine guns, electronic tags that cling to soldiers' clothing and call in mini-missiles, or fields full of simple vibration sensors—all these could one day provide substitutes for anti-personnel landmines, according to a report from the US National Academy of Sciences.

In 2006, the US is set to belatedly join 139 other countries in agreeing to the Ottawa Convention outlawing anti-personnel landmines, so Congress asked the academy to assess alternatives. George Bugliarello of the Polytechnic University in New York, who chaired the academy's committee, says their aim was to identify "Ottawa-compliant" technologies that discriminate between troops and civilians.

Most antipersonnel landmine alternatives include what the military call a "man-in-the-loop"—someone who assesses the threat before a weapon is activated. One such system recommended by the academy is the "nonself-destructing" mine. When someone steps on it, it alerts an observer who decides whether to detonate it or not. But academy committee ...