According to scientists and officials, the United States’ weapons laboratories, armed with some of the fastest computers on the planet, are peering ever deeper into the mystery of how thermonuclear explosions occur, gaining an understanding that in some ways goes beyond what was learned from explosive tests, which ended in 1992.

American researchers are unveiling a new tool for detecting illegal nuclear explosions: the Earth's global positioning system (GPS). Even underground nuclear tests leave their mark on the part of the upper atmosphere known as the ionosphere, the researchers discovered, when they examined GPS data recorded the same day as a North Korean nuclear test in 2009. Within minutes on that day, GPS stations in nearby countries registered a change in ionospheric electron density, as a bubble of disturbed particles spread out from the test site and across the planet.

The Obama administration plans to soon begin to "educate" the U.S. Senate and the public on the strides made in scientific research and nuclear blast monitoring since the country last considered the Comprehensive Test Ban Treaty, a senior State Department official said yesterday

A senior U.S. defense official last week voiced confidence in a newly defined "reuse" approach to modernizing nuclear warheads that some scientists have called into doubt.

President Barack Obama’s signing of a nuclear arms reduction treaty with Russian President Dmitry Medvedev took so long to conclude it has jeopardized Obama's chances to achieve another nuclear goal: Senate ratification of a nuclear test ban treaty.

In a challenge to the White House, the nation’s nuclear weapons laboratories have warned Congress that federal programs to extend the life of the nation’s aging nuclear arsenal are insufficient to guarantee the viability of the weapons for decades to come.

The Obama administration said Thursday that it would ask the Senate to ratify the Comprehensive Nuclear Test Ban Treaty, more than a decade after President Bill Clinton failed to convince the treaty’s opponents that the American arsenal could deter adversaries without ever setting off nuclear explosions.

The Comprehensive Nuclear-Test-Ban Treaty Organization built seismic station PS44 near Ashgabat, Turkmenistan, a “few kilometers” from the Central Asian country’s southern border with Iran. The site adds to the group’s 337 stations worldwide designed to detect seismic activity and atmospheric radiation caused by nuclear explosions.

Jessica Mathews argues that the case against the Comprehensive Test Ban Treaty has collapsed in the ten years since the U.S. Senate last rejected it in 1999.