There are still 12,000 nuclear warheads on earth.

That number is unacceptable, but it represents a more than 80% reduction from the Cold War. Trump’s announcement threatens to reverse this progress.

This is a perilous moment. Nuclear-armed states are updating their arsenals and some are expanding them. New START, the last bilateral treaty constraining the US and Russian arsenals, expires in February.

On the national level, it will undermine the United States’ own strategic advantage, which it gained by conducting more nuclear tests than any country on earth. A return to testing will benefit US adversaries by allowing them to catch up in nuclear research and weapons development.

If the US breaks its 30-year moratorium on nuclear tests, China and Russia will likely return to wide-scale explosive testing. On the international level, this will heighten the risks of great power competition and increase the likelihood that strategic tensions lead to nuclear catastrophe.

While the details of this policy shift are unclear, including whether Trump is referring to missile testing or explosive nuclear tests, it threatens to upend relations between nuclear-armed states and push the world deeper into a new arms race.

1. The U.S. does not have the most nuclear weapons (Russia does).
2. Truly don’t even know what he could mean by the second sentence. That did not happen.
3. China will not be even with us in 5 years.
4. No other country is conducting nuclear weapons testing. “On an equal basis” = not at all