"Old Soviet Nuclear Site in Asia Has Unlikely Sentinel: The
U.S."  "KURCHATOV, Kazakhstan — Twenty years after the Soviet
Union collapsed and tens of thousands of soldiers abandoned
their posts at this remote site in northeastern Kazakhstan, the
footprints of another great power — the United States — are
increasingly visible.  The United States Defense Department has
paid for aerial drones to spot intruders, and for motion
detectors that signal when a person, or a horse or a car,
crosses into restricted territory. The classified project aims
to keep terrorists away from what the Soviets left behind in
patches of earth and a warren of tunnels that they used for
atomic testing: among other things, plutonium and highly
enriched uranium that Western scientists fear could be used to
build an improvised nuclear device.  Protecting this material
has meant teasing out nuclear secrets that have been kept for
decades. Russia is warily sharing archival material about
Soviet-era tests, and the United States is paying to