The trove of recently leaked intelligence documents related to the Ukraine war should prompt Americans to start asking tough questions about our involvement in that conflict, which one of the documents, a Feb. 23 overview of fighting in Ukraine’s Donbas region, describes as a “grinding campaign of attrition” that has reached a “stalemate.”

U.S. taxpayers have poured nearly $80 billion into this war over the past 14 months or so. At what point are we allowed to ask whether a …