Make no mistake: Eric Cantor sides with the strong-on-defense wing of the GOP. In a Presidents Day speech prepared for delivery at the Virginia Military Institute, the House majority leader offers a full-throated rebuke of the “isolationist sentiment” he says caused the United States to hesitate to enter World War II and again threatens to unleash global horrors. The speech is aimed at President Barack Obama, accusing him of bungling just about every foreign policy challenge he has faced as commander in chief, from Syria’s civil war to the attempt to reset relations with Russia. “America’s friends worry we have...