On this day in 1944, the liberation of Western Europe began with immense sacrifice. In a tribute delivered 40 years later from a Normandy cliff, President Ronald Reagan reminded us that “the boys of Pointe du Hoc” were “heroes who helped end a war.” That last detail is worth some reflection because we are in danger of forgetting why it matters. American soldiers, sailors, airmen and Marines joined allies and took the fight to the Axis powers not as a first instinct, but as a last resort....