President Donald Trump ordered the Department of War to resume testing nuclear weapons “on an equal basis” with Russia and China on Thursday, a practice halted by the U.S. in 1992.

The announcement gave rise to fears of the revived possibility of nuclear doom from some, and outright confusion from others. Defenders praised the move as a tit-for-tat response to saber-rattling from Russia and China, while critics decried it as a reckless move with wide-reaching consequences.