Portugal Colonial - Trump call for nuclear tests sows confusion

The US president baffled foreign government and nuclear weapons experts alike when he said he had ordered the Pentagon to start nuclear weapons testing "on an equal basis" to China and Russia.

Speaking to reporters aboard Air Force One, the US president also said that it had been "many years" since the United States had conducted nuclear tests and it was "appropriate" to start again because others are testing.

The last time Russia officially tested a nuclear weapon was in 1990, and the United States last tested a nuclear bomb in 1992.

North Korea is the only country to have conducted nuclear weapons tests this century.

Heloise Fayet, a researcher at the French Institute of International Relations, said it was not immediately clear what Trump meant -- or whether the United States might be preparing to tear up the global rulebook and resume nuclear weapons testing after a 33-year hiatus.

"Either he is talking about testing missiles, but the United States already does that," she said.

"Or he is talking about subcritical tests, but I don't think he has mastered that level of technology," she added, referring to low-yield tests authorised by the Comprehensive Nuclear Test Ban Treaty.

"Or he is talking about real tests, but no one does that except North Korea."

Trump's announcement came after President Vladimir Putin said that Russia had in recent days tested nuclear-powered, nuclear-capable weapons -- the Burevestnik cruise missile and the Poseidon underwater drone.

On Thursday, the Kremlin sought to cool tensions, saying those tests did not constitute a test of an atomic weapon.

- 'Extremely complicated' -

William Alberque, a former head of NATO's nuclear non-proliferation centre, pointed to Trump's lack of clarity.

"Initially, I thought Trump was reacting to Russia's announcements about new systems like the nuclear-powered cruise missile Burevestnik and the Poseidon torpedo. So my first interpretation was that Trump was referring to system testing, not warhead testing," he told AFP.

But like all nuclear powers, the United States already tests its weapons.

In September, the United States carried out tests of its nuclear-capable Trident missiles.

There is also a possibility that Trump might have meant the so-called subcritical nuclear tests, said Fayet.

"We are almost certain that Russia and China are conducting subcritical tests that release a certain amount of energy but remain within the limits," said Fayet.

But "in the United States, they are conducting more restrictive subcritical tests, with no energy release, no heat and no critical reaction".

Trump could demand to catch up, she said.

"But it's an extremely complicated subject, and I don't know if he is at that level of subtlety," she added.

- 'Chain reaction' -

Alberque said that after closely examining Trump's statements, he was inclined to think that "he's talking about warhead testing."

Many Trump supporters have long lobbied for a resumption of nuclear testing, despite the existence of computer-based simulations as well as serious negative international consequences.

"America must prepare to test nuclear weapons," the influential conservative think tank Heritage Foundation said in a report in January, referring to a "deteriorating security environment".

Some experts said Trump's latest pronouncements were a gift to the governments of Russia and China.

In 2023, Putin ordered the Russian defence ministry and the nuclear agency Rosatom to "ensure readiness for testing Russian nuclear weapons".

"We know for certain that some figures in Washington are already considering the possibility of conducting live tests of their nuclear weapons," Putin said during his address to the Federal Assembly in February, 2023.

"But if the US conducts tests, then we will too."

Daryl Kimball, executive director of the Washington-based Arms Control Association, said on X that Trump's policy was "incoherent: calling for denuclearisation talks one day; threatening nuclear tests the next".

The resumption of such tests "could trigger a chain reaction of nuclear testing by US adversaries, and blow apart the nuclear Nonproliferation Treaty," Kimball said.

A.F.Rosado--PC