Underground nuclear tests have been the biggest roadblock to a comprehensive test ban. How are these explosions detected, and how reliably?

As missiles get faster, the Navy can’t continue to rely on dumb armor. What can ship designers learn from dirt and beanbags?

What would happen to the global climate after a nuclear war between India and Pakistan? Study says the planet would be dark and cool for 10 years. How much would food production decline?

20 years ago, ecotourism was promoted as a way to save natural systems, and the people who lived in them. We ask: Is ecotourism a force for good, or just another form of “greenwashing”?

New analysis of post-traumatic stress disorder among American Vietnam vets find 19 percent had PTSD after serving in combat. The greater the exposure to combat, the higher the rate of PTSD.

What are the health effects of low-level radiation? How much cancer results from a small dose increase? If the hazard is small, are we wasting money on radiation protection? Lessons from Hiroshima and Chernobyl.

As weapons proliferate, we wonder: exactly how do you make a nuke? How many nations have this ability? How can we track proliferators?

In mid-2004, U.S. jails and prisons held 2.1 million people. What are the psychological effects of imprisonment? How do POWs survive prison and torture? Can these scars be healed?

Scientific journals choose self-censorship, decide not to publish articles related to biological weapons, bioterrorism and national security. Is this a necessary change in scientific tradition, or an over-reaction to a fearful political climate?

Existing nukes may not exhaust the possible nukes. What other weapons could appear on the nuclear shelf?