Robert Kaplan notes that the current military catchphrase is boots on the ground. In the future, it could be hulls in the water:
The period of 1890 to 1989 was about dominance: controlling vast oceanic spaces by making sure your national navy had more ships than those of your competitors. This era reached its zenith in 1945, when the U.S. Navy and its vast fleet of supply ships numbered 6,700. With no peer competitor in sight, the president and Congress moved quickly to cut that Navy, along with the standing Army, considerably. By 1950, the United States had only 634 ships.
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For the remainder of the Cold War, the Navy was able to hold the line at roughly 600 ships, in part by arguing for its importance in supporting a ground war against the Soviet Union and its allies — it would be the Navy’s job to get soldiers to the fight, and to soften up the battlefield with offshore firepower.In 1991, the Gulf War provided a live-action demonstration of this capacity. Even so, by 1997, post–Cold War budget cuts had reduced the Navy to 365 ships. (In the Quadrennial Defense Review of that year, the Pentagon established a “red line” of 300 ships, below which the Navy would not go.) Of course the 300-ship Navy could still, in the words of Robert O. Work, vice president for strategic studies at the Center for Strategic and Budgetary Assessment, in Washington, “pound the snot” out of primitive challengers like Iraq, Iran, and North Korea, because the precision revolution in weaponry enabled, for instance, a single wire-guided missile from a U.S. destroyer to accomplish what in Vietnam had required wave after wave of carrier-based planes.
Still, the fewer vessels you have, the riskier each deployment, because a ship can’t be in two places at once. Due to the rapid increase in ship-borne trade, globalization favors large navies that protect trade and tanker routes. Additionally, while the United States remains a great naval power, it is no longer a maritime power; that is, we don’t have much of a merchant fleet left to support our warships in an emergency. We’ve been priced out of the shipbuilding market by cheap-labor countries in Asia.
All of this puts us in a precarious position. History shows that powerful competitor navies can easily emerge out of nowhere in just a few decades. The vast majority of American ships that saw combat in World War II had not even been planned before the spring of 1941. The Indian navy, which may soon be the third-largest in the world, was not on many people’s radar screens at the close of the Cold War. Nor, for that matter, was the now-expanding Chinese submarine fleet. Robert Work told me that he believes the eventual incorporation of Taiwan into China will have the effect that the Battle of Wounded Knee had on the United States: It will psychologically close an era of national consolidation for the Chinese, thereby dramatically redirecting their military energies outward, beyond their coastal waters. Tellingly, whereas the U.S. Navy pays homage to Mahan by naming buildings after him, the Chinese avidly read him; the Chinese are the Mahanians now.
Then there is the Japanese navy, which now operates 117 warships, including 16 submarines. In a sense, we’re back to 1890, when a spark of naval competition among rising powers like Japan, Germany, and the United States left Britain unable to maintain its relative advantage.
To understand our tenuous grip on military power, Kaplan recommends two classics on naval power: Mahan’s The Influence of Sea Power Upon History, 1660-1783, which was written in 1890, and Julian S. Corbett’s Some Principles of Maritime Strategy, which came out in 1911. (Both are included in Roots of Strategy Book 4.)