As Emily Thornberry, Shadow Defence Secretary, closes the consultation period on her defence review, critics of the review have been engaging on the substance. They worry that minds currently are just a little too open to alternatives for comfort, and that a non-Trident alternative could become Labour policy. Kevan Jones, former junior Defence Minister and consistent Trident advocate, this week sent around Labour MPs a detailed critique of the air-launched, F35/B61-12 option promoted by CentreForum's Toby Fenwick. This development deserves attention beyond the technical community, because being a great deal cheaper than Trident renewal and offered up as a serious minimum deterrent, it could come to occupy that elusive middle ground for those seeking compromise on the issue, a step down the nuclear ladder without stepping off it quite yet. It is likely to become more compelling as the costs of Trident escalate and the uncertainties over its effectiveness grow.
Fenwick's proposal involves scrapping the plans to construct ballistic missile submarines currently in development and instead deploying a UK free-fall bomb based upon the new US B61-12 design. His proposal, using dual-capable F-35 aircraft the UK is buying from the United States anyway, takes at face value the UK policy of deploying a minimum nuclear deterrent. This implies the capability to deliver just enough damage on an aggressive Russia that even were the UK to face them alone they would not consider the damage sustained acceptable whatever the perceived benefit. Minimum deterrence is all too often defined in official statements in relation to what the UK currently deploys, rather than any realistic assessment of the psychology of any possible future Russian leadership. Jones' assessment repeats this fallacy. The fact that a system based upon the free-fall bomb is less capable is irrelevant if it meets the minimum deterrence criteria, and could be an argument in its favour.
Much store is placed upon the scenario of Britain facing Russia alone. Of course, even a United States led by a President Trump or Sanders would never stand by if a resurgent Russia were to attack Europe and gain a major and global-threatening strategic advantage. But it is believed this independent capability complicates the calculations of any potential aggressor and assures the Americans that Europeans are taking their fair share of the nuclear burden. Readers can make their own mind up whether this justifies the risk, expense and damage to international non-proliferation efforts.
Nevertheless, Fenwick bases his proposal on just such criteria, and picks a high bar - the Joint Intelligence Committee's Duff?Mason assessment from the late 1970s at the height of the Cold War. Fenwick's detailed modelling shows a highly coordinated British attack upon Russian air defences immediately prior to delivering nuclear bombs upon a heavily defended St. Petersburg. Contrary to Jones' assertion, there is nothing in the Duff/Mason criteria that asserts an attack has to be missile based.
As I outlined in a response to Fenwick's proposal in February 2015, the Trident SSBN system based upon a continuous patrolling posture is inflexible and blocks the UK's ability to engage in further disarmament moves. As a dual-capable system using weapons platforms and delivery systems that have conventional missions, Fenwick's proposal avoids the scale of dedicated capital investment to nuclear weapons that Trident commits us to, and would be the obvious choice of platform for the flexibility to take further steps down the ladder, if we are to field nuclear systems beyond the life of the existing Vanguard submarines. Indeed, Fenwick - a former HM Treasury official - estimates the nuclear specific capital costs of such a system at substantially less than £10bn, less than a quarter of the current Successor SSBN costs.
Jones' assessment includes a great deal of well-argued, balanced detail on NATO's burden-sharing arrangements, rightly highlighting many of their shortcomings that arise from the dual-key arrangements. His forthright statement that these arrangements offer little credibility and that tactical nuclear weapon systems are dangerously destabilising have much to be commended. But this is hardly relevant to a British replacement of Trident.
The critiques of the B61-12 that Jones cites from my colleagues in the United States are based upon its comparison with earlier generations of free-fall bomb. The B61-12 is simply more accurate and useable and therefore dangerous. But the relevant comparison for our purpose is with the capabilities of the Trident missile and warhead. Trident can land a sub-strategic nuclear warhead with minimal warning and with extraordinary accuracy. In contrast, the F35 B61-12 combo would require a very public, concerted attack with some warning that would involve the loss of the majority of the aircraft on the bombing run. It is difficult to see how a shift from Trident to a free-fall bomb makes the system more useable and therefore destabilising, and there is no a priori basis for Jones' statement that a more visible deployment of nuclear weapons is more escalatory. Equally, Jones' criticism that the risk of aircraft losses and therefore leaving the UK unable to conduct conventional strikes rather misses the point that a UK nuclear strike is only conceivable in a state of general war - and that there is unlikely to be much of the UK left to return in the event of a Russian nuclear attack on the UK.
Indeed, if you believe in nuclear deterrence there is a strong case that a bomber-based nuclear force, with several levels of preparation, offers more chance of signalling at a time of crisis.
It is argued that flexible dual-capable systems present other signalling problems. How could Russia tell whether an approaching British squadron of F35 aircraft were carrying nuclear bombs? But if the UK were to be flying such a large squadron in hostile formation towards Russia could we not reasonably say that the deterrence mission had by then failed? Large scale conventional hostilities between nuclear armed states are not actions we should be contemplating with any sense of comfort.
Jones also claims that a British version of the B61-12 would require a testing programme. It is true that unarmed bombs would be tested for their flight and delivery characteristics (as the US is doing right now), but as the B61-12 uses the well-proven B61-3 warhead there would be no need for nuclear tests. The UK has free-fall bomb designs on the shelf, a mission relatively simple when compared to the stresses for warheads from ballistic missile flight.
His conclusion that NATO's nuclear strategy depends upon British Trident springs from nowhere. On the contrary, extensive discussions I have had with those on the 'front-line' in eastern Europe suggest they focus their assurance entirely upon US strategic nuclear systems. Indeed, the paper that Jones extensively cites, by Karl-Heinz Kamp and Maj Gen Robertus Remkes, explicitly refers only to US Strategic Nuclear Systems as the backbone of NATO's nuclear posture (the only mention of Britain's nuclear contribution being in a footnote reference to formal NATO statements).
The strongest pro-nuclear argument against Fenwick's proposal is that the aircraft are vulnerable to air defences whilst on their attack run. He does not claim that the British F35 force would survive the attack (as Jones claims), but simply that there would be a very high confidence of it penetrating defence forces with a high attrition rate, and deliver several nuclear bombs on St Petersburg. Bear in mind the circumstances. We are talking about a nuclear war.
Airfields and ships are vulnerable of course to pre-emptive attack. But two things should be considered. First, as Fenwick correctly models, the UK will have 7 to 9 minutes warning from Fylingdales of a ballistic missile launched from Russia, allowing time for the alert aircraft to scramble from their bases. Second, the assumption, repeated by Jones, that Trident is invulnerable is open to question. The near future is likely to see large numbers of high tech miniature sensors based upon unmanned platforms. Even in peacetime submarines can go missing, be isolated, or be taken out secretly in international waters. An attack on dispersed airfields in Britain or a very visible and well defended aircraft carrier would be a more explicit act of war.
Jones' paper shows elements of careful research. Someone has put a great deal of time into it. But it fails to land a convincing blow on one of Trident Successor's principle nuclear alternatives. There may be other important reasons why Fenwick's proposal would be undesirable; if so, they should be considered. But as it stands, if the UK is to field a nuclear weapon system beyond the Vanguards, Fenwick's dual-role plan coupled to significant improvements in the conventional forces deserves serious consideration.