The most alarming aspect of the unfolding crisis in the Middle East isn't how many actors are jumping in. It's who is opting to stay out. Hamas, Hizballah and Israel are directly involved; Iran and Syria by proxy; Lebanon against its will. The U.N. is dispatching its mediators; the European Union is contemplating doing the same. But the U.S., despite colossal strategic stakes, threats to its own security, potential repercussions in Iraq, not to mention staggering loss of life, remains on the sidelines. The world's sole superpower is also its only no-show.
This is by design. From early on, the diplomacy...