Saturday, August 15, 2009

Submarines and Space Power

By Nader Elhefnawy

Reproduced with permission from the October 2001 issue of The Submarine Review, a quarterly publication of the Naval Submarine League, P.O. Box 1146, Annandale, VA, 22003.

At the close of his book, The Price of Admiralty, military historian John Keegan presents the vision of an ocean empty of warships, the battle for the seas waged by aircraft and missiles flying above it and submarines sailing below it. While Keegan was writing of the future, the stage was set for that picture in World War II, when the aircraft carrier and the submarine eclipsed the battleship as queen of the high seas.

Against the airplane and the submarine, the traditional gunboat had simply become "senile." Even if reports of the gunboat's impending demise seem greatly exaggerated, its vulnerability to aerospace and subsurface attack have only grown since that time. In the Falklands War, for instance, aircraft were again at the center of the conflict, Britain's task force built around two carriers and Argentina attacking that task force principally with aircraft. American naval actions against Libya in 1986, and Iraqi naval vessels in 1991, were conducted in much the same way, with air power. Submarines have achieved similar successes. In the 1971 Indo-Pkistani War, and the Falklands War, the mere presence of submarines was enough to keep the most powerful ships in a surface fleet out of the battle area.1 And despite the Soviet Union's ambitious surface fleet program, it was always Soviet air power and Soviet submarines that were of concern for the Western planners who had looked to a Third Battle of the Atlantic in the 1970s and 80s.

To the threat from manned aircraft has been added the threat from space, and the anti-ship missile, which was critical in many of the above-mentioned conflicts. In fact, it has made the threat from the air so great that even the carrier is itself under threat. Moreover, these threats are only expected to grow. One of the few lasting trends seems to be that missiles will "continue to become more and more accurate and to have greater and greater ranges at faster and faster speeds."2 In large part, this will be because of advances in technologies permitting surveillance, navigation and targeting from space.3 It is now taken for granted by a great many military experts that future naval wars will be won or lost not on the high seas, but in the higher ground of outer space. As George and Meredith Friedman observe in The Future of War, space-based reconnaissance platforms linked to missiles will be enough to choke the sea lanes.4

However, what their argument misses is that it may not be enough to control space. Wars for dominance of the oceans will also be fought underneath the seas. The reason for this is that the undersea world is perhaps the only area of military operations still impervious to surveillance from space, and which may hope to remain so for the foreseeable future. The sea surface presents a barrier that cleaves the battlespace in two, a surface environment where aerospace power is supreme, and a subsurface one dominated by the submarine. The one way in which this could change is the development of a non-acoustic sensor technology that would render the seas transparent. Efforts to develop such technologies date back to World War II.5 With the appearance of low-frequency sonar, many of them were shelved, but some have been put into practice, such as MAD (Magnetic Anomaly Detection), electronic intelligence and periscope and snorkel detection radar. Efforts continue in other areas, and these became an object of media attention in the recent investigations of Chinese intelligence's penetrations of American R & D.

It is not unthinkable that some of these efforts could achieve a long-awaited breakthrough. However, it should be remembered that history is littered with false breakthroughs in this area, such as laser radar for picking up on underwater objects, or sensors which detect submarine phenomena, like the radar, thermal and magnetic characteristics a submarine produces as it moves through the water. Additionally, the future of non-acoustics is difficult to evaluate, because there are so many disturbances which can mask the movement of submarines, or easily be mistaken for them.6

Even if these techniques meet with some success, submarines are likely to retain much of their inherent stealthiness. Consider, for instance, one of these methods, the location of submarines by the water they displace, the tiny "hump" in the surface of an ocean they make as they pass underneath.7 Undeniably, this is a far smaller radar signature than even the stealthiest of surface ships possess. Laser beams, moreover, can penetrate water down to a hundred and fifty meters but no more, so that present-day subs often cruise outside their range.8

If anything, the submarine's stealth might grow in the future. The same research that might improve anti-submarine warfare techniques cuts both ways. A better understanding of potential means of non-acoustic detection will make it possible to build even stealthier subs.9 Future submarines may also be deeper-diving and quieter, with stronger hulls, so that a revolution in anti-submarine weapons as well as sensors would be necessary.10 Submarines may also have more sophisticated means of defending themselves, such as improved electronic wafare technology.11 The establishment of bases on the seabed, about which some writers have speculated, would allow submarines to stay out at sea even longer than is presently possible.

In short, even as space forces battle for supremacy in the heavens, the submarine could retain its freedom of action, which is what has made it so deadly. This will allow submarine forces to accomplish two of any major fleet's primary goals with minimal interference from aerospace forces: attack shipping and to project power inland.

Even were the oceans to become empty of warships, they would not become empty of shipping. No one expects the reliance of the world economy on the sea lanes to end in any foreseeable future: water transport has always been, and probably always will be cheaper than the alternatives. Additionally, where countries once fought for the freedom to travel on the sea, now they fight for the riches of the sea, and the seabed. The right to fish or drill for oil in particular waters has already precipitated several military clashes, and is considered likely to cause many more in the future.12 Ocean mining, should it seriously get under way, will only increase the economic importance of the oceans, and that of the ships traveling across them.

While in recent decades increased attention has been focused on ballistic missile submarines, and on attack submarines dedicated to hunting other submarines, preying on merchant shipping has been the submarine's traditional mission. German U-boats nearly drove Britain to capitulation in the First and Second World Wars. Where the German submarine force failed against Britain, America's succeeded against Japan in the 1940s. While no comparable conflict has been fought since 1945, the blockade has remained an important instrument of sea power, as in the "Tanker War" of the 1980s. While the tanker war was conducted primarily with air- or shore-battery launched anti-ship missiles, the submarine's stealth may make it not merely a superior missile platform, but the key weapon in future blockades. Rocket-powered weapons like the Russian Shkval (which at present has no Western equivalent) may also give the torpedo new significance. Missiles can be seen launching from space; the same can not be said of torpedoes, against which space forces would prove much less useful.

Just as submarines can fire missiles at ships, they can also fire them at targets on land, and have been doing so since the 1991 Gulf War, when American submarines first launched Tomahawks at targets in Iraq. However, submarines have long had one great disadvantage, their payloads, which are much smaller than those of larger, more capacious surface vessels.13 This could also change in the foreseeable future, ironically because of improvements in the technology that has been sweeping the seas clear of gunboats.

It has long been observed that cruise missiles make every warship an aircraft carrier on the cheap.14 At some point, it could make smaller warships a substitute for today's carriers, and it is worth noting that the land-attack Tomahawk cruise missile is now the main armament of the Ticonderoga, Arleigh Burke and Spruance ship classes.15 However, the capabilities of the existing missiles are limited compared with those of manned attack aircraft. Missiles like the Tomahawk are not very versatile: they can not be used to attack mobile or dispersed targets like armored formations. They also carry very small payloads: their one thousand pound warhead falls far short of what an attack plane like the F/A-18 "Hornet" can carry, let alone its replacements. However, improvements in cruise missile design will close the gap between missile and aircraft.

Already, analysts have speculated about a submerged version of the now-canceled arsenal ship, which would have carried Tomahawk cruise missiles as well as a navalized version of the Army's Tactical Missile System which would have allowed it to provide fire support for ground forces.16 In the nearer term, they have also thought about converting nuclear submarines into dedicated cruise missile platforms. It has been calculated that a submarine with seventy-five to one hundred Tomahawks in vertical launch tubes would make an acceptable substitute for a carrier.17 Studies have shown that currently existing ballistic missile submarines could do even better-a properly modified ballistic missile submarine could carry 288 such missiles.18 While this falls far short of the mix and number of weapons a carrier could deliver, it is nonetheless equal to the number of cruise missiles fired during the entire Gulf War.

In the nineteenth century, submarines had been attractive to many navies because they seemed to be a way of offsetting the naval superiority of countries with more powerful surface fleets. This may be the case in the twenty-first century if the oceans are not rendered transparent. For instance, a "large peer competitor", finding itself unable to challenge American surface (aerospace) superiority, may concentrate on defeating it through submarine actions, as Germany tried to defeat Britain during the world wars.

Picture a future Battle of the Atlantic, in which air and space forces, satellites and missiles, fight for the skies while submarines sink shipping and conduct missile attacks on land targets. Because the sea surface may continue to present a barrier between air power and submarine power, victory in the sky or in outer space will not necessarily translate into a victory in the submarine war. Surface ships, it has been argued before, will probably find themselves outmatched. In the end, stopping the enemy's submarines will require attack subs dedicated to destroying their brethren, the most effective anti-submarine weapons yet devised. And once again, victory will not be a question of inventing a decisive weapon, but rather achieving the proper mix of weapons, which will conceal one's vulnerabilities while striking at the enemy's-a mix in which the submarine will likely hold a proud place.

1. In the Falklands, the sinking of the Argentine cruiser General Belgrano by the British nuclear submarine the HMS Conqueror is widely credited with compelling Argentina to confine its surface ships to port.
2. James L. George, History of Warships (Annapolis: Naval Institute Press, 1998), 263.
3. The Tomahawk cruise missile is an example of the connection between missile and space technology. The Tomahawk's terrain contour matching (TERCOM) computer works by matching satellite photographs against the pictures captured by the digital camera in its nose. The Block III version of the Tomahawk also uses a Global Positioning System to get fixes on its location.
4. These, of course, may be succeeded by weapons launched directly from space.
5. Norman Friedman, Seapower and Space (Annapolis: Naval Institute Press, 2000), 201-206.
6. Friedman, Seapower, 206.
7. Friedman, Seapower, 210.
8. Ibid.
9. Friedman, Seapower, 205.
10. An interesting discussion of the future of submarine warfare can be found in a paper, "21st Century Naval Warfare" by three Chinese naval officers, Captain Shen Zhongchang, Lieutenant Commander Zhang Haiyin and Lieutenant Zhou Xinsheng. It appears, translated by Michael Pillsbury in his book Chinese Views of Future Warfare (Washington D.C.: National Defense University Press, 1997). This material also appears, summarized, in an article of the same name by Pillsbury in James R. Liley and David R. Shambaugh, eds., China's Military Faces the Future (New York: M.E. Sharpe, 1999).
11. Radar provides a useful analogy here. It was supposed to render the sky "transparent," to cut through darkness and bad weather to locate aircraft, but stealth technology and sophisticated defense suppression tactics have gone a long way to nullifying this advantage.
12. The South China Sea is a particularly good example of a scene of such disputes. Since 1988, there have been more than a dozen military incidents in that region.
13. Raja Menon, Maritime Strategy and Continental Wars (Frank Cass & Co., 1998), 187.
14. Menon, 194.
15. Menon, 193.
16. Dennis M. Bushnell, "The Shape of Things to Come," Undersea Warfare Magazine (Winter 2001). In this article, Bushnell describes a highly automated, spherical, deep-water ship designed for stand-off operations and capable of burst speeds.
17. Norman Friedman, U.S. Submarines Since 1945: An Illustrated Design History (Annapolis: United States Naval Institute, 1994), 214.
18. Menon, 187.

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