In 1984 on the 40th anniversary of D-Day, Ronald Reagan ascended the windswept stage of Pointe Du Hook, Normandy to commemorate one of the greatest sacrifices in the defense of freedom the world had ever seen. “We in America have learned bitter lessons from two World Wars,” Reagan declared. “It is better to be here ready to protect the peace, than to take blind shelter across the sea, rushing to respond only after freedom is lost. We’ve learned that isolationism never was and never will be an acceptable response to tyrannical governments with an expansionist intent.” Nearly 40 years after...