The world is a better place because Adolf Hitler did not preserve his conquest of the European continent, and because the Greater East Asia Co-Prosperity Sphere of Hideki Tojo and his militarists imploded at Midway, Guadalcanal, and Okinawa. Italy and the Mediterranean were far better off without Benito Mussolini and his mad plans for a renewed but debased Roman Empire, which ended on his own Italian soil at exotic-named places like Anzio and Monte Cassino.

The dream of Soviet rulers from Stalin to Brezhnev was a global gulag overseen from the blood-stained Communist Kremlin. It ended only through the 50-year deterrence of the American military. South Korea, the Philippines, and Taiwan are somehow still free and independent — and would not be without American carriers, jets, and submarines.

Our generation’s own rogues’ gallery of killers — Saddam Hussein, Slobodan Milosevic, Manuel Noriega, and the Taliban — have lost their tyrannies. If South America chooses to become Communist, it will be by its own volition and not because of an unfettered cross-border invasion from Cuba, Nicaragua, or Venezuela. Even our enemies can export or import oil freely from the Middle East without worries of armed intervention or piracy — as long as an American carrier is nearby in the Gulf.

It seems as if the more Europe disarms and gnashes at the United States, the more we are there when it needs us. If an ascendant China decides to bully Japan or Taiwan in earnest, only one country can thwart it. No one will call the European Union or Russia should North Korea tomorrow cross the 38th parallel or Iran decide to launch a missile. If Turkey rearranges the border in Cyprus or claims airspace over the mid-Aegean, anti-American Greece will turn pro-American. There will be no second Holocaust, in part because of American military support for Israel....