Earlier this month War on the Rocks carried an interview with General David Berger, commandant of the U.S. Marine Corps. The interview was mostly about personnel policy, but toward the end the interlocutors dwelt briefly on strategy and operations in the Western Pacific. Asked about the danger to fixed U.S. bases from Chinese missile salvoes, the commandant seemed to downplay fixed facilities and defenses as a warfighting implement.
Instead, said Berger, it’s imperative to “prevent the linear approach, like their wall against our wall, first island chain against what they have in mainland China—that sort of linear facing off at each other. Okay, that’s definitely not a healthy approach.” In other words, he believes emplacing marine garrisons all along the first island chain in more or less static positions would court defeat at the hands of People’s Liberation Army (PLA) rocketeers, who have at their disposal an imposing array of ballistic missiles boasting various ranges.
And Berger may well be right. Think about it in mathematical terms. A defensive perimeter is a line, and a line is made up of infinitely many points in continuous series. It’s tough to be stronger than a foe at infinitely many points on the map, all the time. An opponent intent on a breakthrough will simply mass forces at some point along the line and puncture it. That’s why military sage Carl von Clausewitz disparages long defensive lines, or cordons. “Lines,” he maintains, “constitute the most ruinous form of cordon-warfare. The obstacle they offer the attacker is worthless without powerful fire to support it. Otherwise it is good for nothing.”
Adds Clausewitz, defensive lines will “have to be very short and thus cover very little of the country, or the army will not be able to defend all points effectively.” To repulse an attempted breakthrough, commanders must be able to supplement ground forces holding the line with firepower delivered at a distance, at any point along the ramparts. How distended a perimeter defenders can hold, then, is a function of geographic distance, terrain, and the reach and volume of precision fire support available to marines, the navy’s fleet, and supporting air forces. It’s worth applying these Clausewitzian metrics to the problem of defending the first island chain from a PLA breakout, and confining the PLA Navy and Air Force to the China seas in the bargain.
A long-dead Prussian can help define the limits of the possible.
Berger continued: “There’s an aspect of ‘home team’ that people have written about in the last month or two that are, I think, helpful here, in terms of analyzing a force on force and who has actually the home-team versus away-team advantage, and what do they really mean?” A couple of U.S. Marine pals and I are the aforementioned people. Last December the Marine Corps Gazette ran our essay exploring how the sports metaphor of the home-team advantage applies to Pacific sea combat. We concluded, to oversimplify, that China enjoys the home-team advantage on a theaterwide scale, but that the United States and its allies have the advantage along the island chain.
If the allies harness that advantage, they may yet accomplish their operational and strategic goals. As opposed to the linear, static approach, General Berger puts the accent on mobility and on defense in depth. Some “stand-in forces,” chiefly unmanned vehicles, will operate west of the island chain, getting in the PLA’s face for scouting purposes. Their handlers will constitute the next layer, and heavier, missile-armed combat forces the next. Marines will move from island to island frequently to evade targeting. Meanwhile submarines, surface warships, aircraft, and sea mines will lurk in and around the straits, plugging them to Chinese military and commercial craft.
To go back to the sports metaphor, think about island-chain defense in football terms. The Georgia Bulldogs won the college national championship Monday night behind a legendary defense. This was not a static defense, even along the line of scrimmage. Even the Bulldogs’ massive linemen were quick and agile. Inventive, highly mobile and deceptive blocking schemes created mismatches along the offensive line, helping defenders contain the Alabama offense and, oftentimes, open gaps through which to break into the backfield in search of a quarterback sack or a tackle for a loss. Alabama, also the possessor of a stout defense, did the same for much of the game.
Meanwhile the defensive secondary operates as a defense in depth in case the offense breaks through the defensive line on the ground or lofts a pass over the line. Defenders operating in space can contain running plays while trying to break up passes or limit receivers’ gains through the air. An impenetrable defensive front is the ideal, just as an impregnable first island chain would be. But this is not reality except against an utterly outmatched adversary. In naval warfare as in football, defense is a hybrid linear/nonlinear enterprise.
Thus has it always been. Think back to military history. Walls are commonplace in history, and yet those who constructed and guarded them seldom regarded these edifices as impenetrable. They too thought in terms of defense in depth. Chinese engineers built the Great Wall to fend off nomads raiding into China from the Central Asian steppes. Yet they assumed there would be breaches. The key was to stage mobile forces to the wall’s rear to quell hostile forces that got through.
The Great Wall’s purpose was to limit and channel breakthroughs, not prevent them altogether. Just as with Clausewitz’s defensive cordons, a wall’s efficacy hinges on geography, terrain, and armed might.
Or if the correlation of forces permits, defenders can use defensive fortifications in an offensive way. Roman legionaries used Hadrian’s Wall, which undulated across the northerly narrow neck of Britain, as a backstop for forward operations in Scotland. If successful, forward operations would prevent incursions into Roman Britain from ever occurring. The Roman model was a highly active model of frontier defense where the Chinese took a more passive outlook.
Humility is the proper attitude when devising doctrine, tactics, and hardware for island-chain defense. If the home-team advantage favors the PLA on balance, the defensive philosophy manifest in the Great Wall may be fitting. But even if so, U.S. and allied commanders should work ceaselessly to amplify their own geographic, military, and alliance advantages—making Roman-style forward operations thinkable. Forceful is better.
Let’s play the game in China’s backfield.
A 1945 Contributing Editor, Dr. James Holmes holds the J. C. Wylie Chair of Maritime Strategy at the Naval War College and served on the faculty of the University of Georgia School of Public and International Affairs. A former U.S. Navy surface-warfare officer, he was the last gunnery officer in history to fire a battleship’s big guns in anger, during the first Gulf War in 1991. He earned the Naval War College Foundation Award in 1994, signifying the top graduate in his class. His books include Red Star over the Pacific, an Atlantic Monthly Best Book of 2010 and a fixture on the Navy Professional Reading List. General James Mattis deems him “troublesome.”