The Defense Advanced Research Projects Agency plans to issue contracts next year to develop a self-repairing anti-tank minefield. For decades, the normal course of business has been to protect an anti-tank minefield with many more anti-personnel mines, which keep infantry from removing the heavier anti-tank mines. It is these anti-personnel mines that are the subject of international opposition. The new plan would replace buried anti-tank mines with self-mobile anti-tank mines laid on the surface of the ground. There would be no anti-personnel mines to protect them. Instead, the mines would be capable of sensing each other, and when a gap develops in the minebelt, mines on either side of the gap would (without directions from outside) move themselves into the gap to close it.--Stephen V Cole