China’s leaders say that the Chinese government has begun to accelerate the development of its nuclear arsenal after reassessing the threat posed to mainland China by the United States.

The Wallstreet Journal said that China’s nuclear effort “long predates Russia’s invasion of Ukraine, but the U.S.’s wariness about getting directly involved in the war there has likely reinforced Beijing’s decision to put greater emphasis on developing nuclear weapons as a deterrent.”

It is believed that Chinese leaders see a stronger nuclear arsenal as a way to deter the U.S. from involving itself in a potential future conflict over Taiwan.

The Chinese government has also accelerated work on more than 100 suspected missile silos that could be used to store nuclear-tipped missiles in remote western regions of China.

American officials and independent security analysts who study nuclear proliferation say they are unsure about what is motivating Beijing’s race to develop its nuclear arsenal.