I exhume World War I not just to mark its centennial but also for a purpose. The war ended after the United States got into the fray. America then reverted to its traditional isolationism and we got, partially as a result, World War II. Now we are reverting once again to a form of isolationism — not as extreme as the first, but the emotion is there, this time even more so on the left than on the right. On the left, anyone who suggested that the U.S. intervene early in Syria, when the Assad regime might have been toppled without resorting to putting boots on the ground, was denounced as a war-monger. I am tempted to say that the United States did nothing. Actually, it was worse than nothing.

Those who believe World War I was caused by a crazy-quilt of alliances among the European powers may shudder at the ones America has now. We are obligated to defend Japan, and we are obligated to defend South Korea. Both countries have issues with one another and, more important, with China. Japan and China contest a group of islands, and China and South Korea contest a different area of the East China Sea. None of this is worth the life of a single person.