This op-ed originally appeared in Defense News , May 10, 2019. President Donald Trump‘s announcement in late April that the U.S. will withdraw its signature from the Arms Trade Treaty is the latest move by an administration innately hostile to nearly every form of international cooperation . In a move that was intentionally deceptive and rife with political theater — with the annual meeting of the National Rifle Association as a symbolic backdrop — the president’s decision damages both America’s security and its credibility. It took more than five years of negotiations to develop the ATT and...