Bombers vs. verifiers: A nuclear race worth winning

The world is in the midst of an unprecedented wave of negotiations aimed at saving global agreements to keep nuclear weapons in check. The Comprehensive Test Ban Treaty, currently gaining momentum worldwide, would be a serious step towards disarmament: no tests effectively means no new weapons. However, opponents fear that the treaty's verification network would not catch small nuclear tests. Last month, that network proved itself by spotting a test in North Korea. Partly as a result, "I think the U.S. will ratify within a year," says Hans Kristensen of the Federation of American Scientists.

Deeper cuts in nuclear arsenals would also require better verification. One problem is missiles with multiple warheads. Inspectors must verify how many warheads are inside sealed tubes, says Andreas Persbo of Ploughshares-funded VERTIC, but they cannot just look inside - the missiles hold secrets their owners are obliged to keep. Last week, VERTIC and British and Norwegian scientists ran the first field trials of a device that could solve the problem.