Just days after the Trump administration indicated it would not be US policy to unseat Syria’s dictator, Bashir al-Assad, Assad grabbed at the opportunity and launched an horrific chemical-weapon attack on civilians in a rebel-held city. The chemical might be the nerve gas sarin. Trump, who in 2013 had urged Obama to avoid deep involvement in Syria, reacted with a cheap shot, blaming Obama’s “weakness and irresolution” for the Syrian government’s chemical attack. The Trump administration did issue a protest of the attack; but it dared not address the possibility that it had given Assad, and possibly his Russian ally, a green light to commit a crime against humanity.