WMD: The Submersible Vector

21 January 2011


Although the public debate over strategy frequently takes the form of men in ties surrounded by microphones and cameras, doing their best to project an image of gravitas, dignity, and respectability, there is more often than not a surreal quality to these oh-so-serious pronouncements. It is almost as though, in planning some of our most complex and expensive strategic weapons systems, that the strategic threat such weapons systems are intended to counter has been plucked out of the clear blue sky. In writing this I have in mind the recently announced strategic missile defense system planned by NATO, which I discussed in NATO’s Gambit.

Now, the threat of ballistic missile attack is not plucked out of the clear blue sky. We know for a fact that there are many nation-states that have developed ballistic missiles and are intent on improving the range and accuracy of these extant weapons systems, and we know that other nation-states are attempting to develop such weapons systems. The great concern is that ballistic missiles could be used to deliver weapons of mass destruction (WMD) quickly and accurately to a distant target. This threat is real. However, it is not the only threat. Moreover, and more importantly, I do not believe that it the most likely threat.

What gives the surreal quality to the plan to develop an ABM system to counter the WMD ballistic missile threat is that political leaders are behaving as though “rogue” nation-states were going to cooperate in fielding a weapons system that conforms to our plans and expectations rather than trying to surprise us. This is not the way the world works. In NATO’s Gambit I wrote:

“I don’t think that the system, once built, would be any more effective than the Maginot Line. If ballistic missiles can be shot down with any degree of reliability, then rogue regimes pursuing weapons of mass destruction, and intent upon their use, would use any means of delivery other than ballistic missiles.”

What other methods of delivery might be considered? The traditional triad of strategic nuclear weapons delivery systems consists of land-based ICBMs, strategic bombers, and submarines. I have already suggested above that ICBMs are too obvious. They have the advantage of being a technology that can be realistically developed (they have ample proof of concept), of striking rapidly, and of being difficult to counter. Difficult, but not impossible. And I think it is fair to say that no “rogue” nation-state, and certainly no terrorist organization, could get its hands on a strategic bomber that could penetrate the air defenses of NATO member states or other advanced industrialized nation-states. This would require either masses of bombers to overwhelm air defenses, more than state-of-the-art stealth, or an inside ability to bring down air defenses by the use of spies or electronic counter-measures. All of these are beyond the efforts of the kind of adversaries NATO plans against.

The 'suitcase nuke' is a known threat that could be delivered by a 'lone wolf' operative.

One common terrorist nightmare that has been discussed is the possibility of a “suitcase nuke,” but this too requires high technology, which must either be developed or purchased. With the nuclear test ban treaty, and the relative ease of detecting nuclear tests, the amount of testing required to produce a reliable, miniaturized suitcase nuke is beyond the ability of all but a very few industrialized nation-states.

Shipping containers are large and anonymous, therefore a threat vector for WMD.

A variation on the theme of suitcase nukes is the scenario of a nuclear device in a shipping container. Millions of shipping containers move around the world every day, and a nuclear device inside such a container would not be limited by concerns of the miniaturization of technology. Awareness of this threat has resulted in the installation of radiation monitoring in ports. This system of monitoring is imperfect, but with time and increased experience and expertise, one could expect a reasonable degree of detection. However, the shipping container vector remains a very real threat.

Efforts are being made to detect nuclear devices in shipping containers.

Another threat is that posed by the third leg of the triad, and always the most stealthy leg of the triad: submarines. Everyone is familiar with the idea of submarines as a strategic threat, but building a missile boat is almost as complex and difficult as the considerations mentioned above in relation to strategic bombers or miniaturized suitcase nukes. Only a very few industrialized nation-states are tooled to produce a submarine that can reliably launch either ballistic missiles or cruise missiles. The latter two threats are particularly of concern because a submarine could move close in to shore and fire off missiles that would strike targets in less than fifteen minutes. Even excellent air defense systems would have difficulty defending against this. But we are protected after a fashion by the barriers to entry presented by this difficult and expensive technology.

U-47 leaving Kiel for Scapa Flow.

There is, however, another submersible WMD threat that I have never seen discussed, although I certainly can’t claim any kind of thorough knowledge of defense-related scenarios. Submarines are ships, and one of the great things about ships as that they can carry a lot of weight, and, compared to tanks or airplanes, they have a lot more space. What this means is that even a crude nuclear device could be constructed within the hull of a basic submarine. While advanced submarine technology is beyond all but a few nation-states, basic submarines are not. Some time ago in The Future of Terrorism I suggested that, given the fact that even drug smugglers are using submarines these days, it would not be beyond the reach of a non-state terrorist entity to build and operate a submarine.

In the same spirit, a non-state entity or a rogue nation-state could build a submarine for the express task of carrying a nuclear device stealthily into the harbor of a great city. Many of the world’s largest, richest, and busiest cities are port cities with busy shipping lanes that might well be infiltrated by reasonably stealthy submarine technology. We recall in this connection that during the Second World War, Günther Prien in U-47 infiltrated the UK’s Home Fleet’s anchorage in Scapa Flow and sunk the Royal Oak at anchor. Take a look at a map of Scapa Flow, and you can see what a feat this was.

The submersible threat vector might be organized in any of several different ways. For example, a remotely operated, uncrewed submarine could be sent into a harbor, or a small suicide crew could pilot a submarine into a harbor, planning to detonate the weapon themselves and die in the delivery, or a crewed submarine could drop a large nuclear device at the bottom of a harbor and escape before its detonation. If it is objected that no rudimentary submersible could make a long distance trip and therefore be able to sneak into a harbor, it is obvious that this is not necessary. A mothership with a hull open to the sea could approach a shoreline (still in international waters), drop a submersible into depths without anyone being the wiser, and the submersible with its WMD aboard would have only a short, stealthy trip to make to deposit its deadly cargo.

HMS Royal Oak

Submarines, as I have pointed out previously, are a robust and well-documented technology. Rudimentary nuclear weapons are nearly as robust and well-documented; the real challenge is not in the design, but in obtaining the materials. No miniaturization would be needed to build a nuclear device into a still relatively small submersible. Moreover, the surrounding water would act as insulation to defeat detection of radioactivity. A reasonable degree of stealth would be sufficient to infiltrate a busy commercial harbor. None of this lies beyond the means of the nation-states that NATO considers dangerous, and it is much more likely to be successful than a rudimentary ICBM.

A real nightmare scenario based on this strategic threat could involve nuclear devices pre-placed throughout the world, and either timed to go off simultaneously or rigged to detonate on some command signal. Imagine the consequences for a maritime nation-state if it suddenly lost all of its major port facilities in one fell swoop. This would be a loss from which there could be no quick and easy recovery.

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A gun-type nuclear device -- the easiest kind to build -- naturally has the same shape as the cylinder of a submarine, so that installing such a nuclear device in a small submarine, even a relatively crude one, would be comparatively easy.

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Grand Strategy Annex

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