With the test moratorium in force, there was no way to refine the design and make it inherently one-point safe.
Russia and France now observe test moratoriums of their own.
The project's troubles began around February, when the Russians ended their 18-month test moratorium.
India would acquiesce to its unilateral test moratorium being turned into a multilateral legality.
President Bush has said it does not adequately protect the nation's security interests, although the Bush administration continues to honor the test moratorium.
In 1958 a voluntary nuclear test moratorium was being considered, spurred by worldwide concern about the fallout of radionuclides from clouds blown around the Earth after atmospheric tests.
With test moratoriums on the horizon, American weapons labs rushed out many new designs.
It was the first Soviet nuclear test since the Kremlin ended a test moratorium that took effect in August 1985.
That not only ended the slim chance that the United States might join in the Soviet Union's 18-month test moratorium.
This test series was scheduled quickly, in order to respond in kind to the Soviet resumption of testing after the tacit 1958-1961 test moratorium.