Adm. Jonathan Greenert made an important observation last fall from the tower of the aircraft carrier USS John C. Stennis while in the Strait of Hormuz on the southern coast of Iran, the world's busiest oil-shipping lane.

The chief of naval operations was sailing in a flotilla that showed off the Navy's overwhelming power to strike at long distances: F-18 fighter jets, Tomahawk cruise missiles and deck guns able to fire a shell 15 miles.

Yet...