CLOUDS ON THE NUCLEAR HORIZON

HOURS before his October 30 meeting with Xi Jinping, Donald Trump announced that he had instructed the US department of war to "start testing nuclear weapons on an equal basis" immediately.

- R SWAMINATHAN

He reiterated the stance in an interview later: "We're going to test nuclear weapons like other countries do." He also accused Russia, China, North Korea and Pakistan of conducting deeply buried underground nuclear tests.

Trump's remarks came in response to Russia's testing of new nuclear delivery systems the Burevestnik, a nuclear-powered cruise missile tested on October 21, and the Poseidon, a nuclear-powered torpedo tested on October 28. His instructions were directed to the US department of war, which oversees missile testing, rather than at the department of energy, the principal authority for nuclear-weapons testing.

The day after the Trump-Xi summit, the US energy secretary clarified that the administration's reference to renewed testing concerned 'system tests'- that is, subcritical experiments intended to verify the performance and reliability of existing nuclear weapons.

However, Trump's ambiguous statements have stirred considerable uncertainty and debate within the nonproliferation and arms control communities, while also prompting reactions from the countries he accused of conducting nuclear tests.

At a meeting with the Russian Security Council on November 5, Vladimir Putin, while reaffirming that Moscow would only restart nuclear tests if the US initiated them, instructed his officials to prepare formal proposals for a potential resumption of tests. Russia also publicly urged the US to clarify what it called "contradictory signals" regarding the resumption of nuclear testing.