The deepening cooperation between China and Russia threatens to overturn decades of international stability in nuclear arms control, according to a top adviser to U.S. President Joe Biden.

To avert miscalculations, nuclear-weapons states must engage on existing and potential threats, from Iran’s atomic ambitions to the use of artificial intelligence for decision-making during crises, Pranay Vaddi, the National Security Council’s senior director for arms control, said in an interview in Vienna.

"We’re entering a different period,” Vaddi said after talks at the International Atomic Energy Agency. "It requires a little bit of experimentation.”