President Trump's post raises technical questions about how and if the United States could "immediately" return to nuclear testing, and political considerations about the signaling behind nuclear testing and who would benefit most from a return to testing.
Hours prior to his meeting with Chinese President Xi Jinping, U.S. President Donald Trump posted on social media:
"Because of other countries testing programs, I have instructed the Department of War to start testing our Nuclear Weapons on an equal basis. That process will begin immediately."
Other than North Korea, no country has tested nuclear weapons since the late 1990s, and the 1997 Comprehensive Test Ban Treaty (CTBT) has been signed by 187 states.
Author's summary: Trump considers restarting nuclear tests.