I am confident that Donald Trump has never heard of Berezina. But he seems to have met his last month. (Berezina, the battle between Napoleon's retreating Army and pursuing Russian forces in November 1812 resulted in heavy French casualties, although the French Army managed to escape across the Berezina River. Ever since, "Berezina" has become a synonym for "disaster" in the folklore of French history.)
What Trump did, as the possessor of five deferments, was to denigrate an American immigrant family, the head of whom had spoken out against Trump at the Democratic National Convention in July. Khizr Khan, who presented himself as a hyper U.S. patriot, withdrew from his jacket a pocket version of the American Constitution. (According to a lengthy profile in The New York Times, Khan had used this device several times in visits to the ROTC program at the University of Virginia, where his son Humayun was studying.) Khan said he wondered whether Trump had ever read the Constitution. In his ensuing days' reply, Trump speculated that Khan's swaddled wife had sat silently beside him on the stage because such a comportment was required by the Muslim religion. (Khizr Khan later disclosed that his wife had written his speech!)
But worst of all, Humayun Khan, one of the family's three sons, was a U.S. Army Captain who had been killed in Iraq. Ironically, this is a Punjabi Muslim family, prized by the British at the time of the Raj as a martial class and the group best equipped to defend British security in India. (Photos of Humayun Khan look every bit the part.)
The lesson for Donald Trump in all this is you don't touch a third rail in American politics that is a Gold Star Mother.
CORRECTION: A previous version of this post incorrectly stated that Army Captain Humayun Khan was killed in Afghanistan. Khan was killed in Iraq.