India must be transparent about its MIRV plans to avert a nuclear arms race in Asia
After the maiden test of the Agni V,the head of Indias Defence Research and Development Organisation (DRDO),V.K. Saraswat,noted that several Agni variants could eventually be mated with multiple independently targetable re-entry vehicles (MIRVs),or multiple nuclear warheads while later conceding that it was not yet government policy to do so. On May 10,he explained: Where I was using four missiles,I may use only one missile. So it becomes a force multiplier given the damage potential.
MIRVd arsenals can be more destabilising than their solo-warhead counterparts. First,accurate MIRVs can enable a state to potentially disarm an opponent completely with only a fraction of the single-warhead missiles that might be required. Coupled with a missile defence system that might intercept any residual forces unhit by MIRVs,a state might be in a position to achieve nuclear superiority. As during the Cold War,this is a blueprint for a nuclear arms race,since adversaries must ensure that they have enough nuclear forces to survive a MIRVd first-strike attempt and saturate any missile defences. Second,against MIRVs,an adversary has an incentive to preemptively destroy a missile force while it is still on the ground,since it can destroy multiple warheads for each hit,as opposed to just trading one-for-one. This gives an advantage to the side that launches its missiles first,the very definition of nuclear instability.
DRDO is attempting to develop accurate MIRVs as well as a multi-layered ballistic missile defence architecture. Saraswat has boasted that such a system will have a 99.8 per cent hit-to-kill probability. Even if this is inflated,to an adversary like China or Pakistan,repeated claims about MIRVs and ballistic missile defences may look like anything but a credible minimum deterrent strategy. But India has a no first use pledge,which makes its pursuit of MIRVs and any thought of attempting a disarming first strike puzzling. So why would India want MIRVs?
There are several possible explanations. Since authoritative views from the government,particularly senior national security officials,on technological developments relating to nuclear strategy have not been aired in the public domain,we and Indias adversaries can only speculate.
The first possible explanation is that deploying MIRVs is not official government policy. Instead,to enhance its organisational prestige,DRDO seeks to indigenously develop the same capabilities,including MIRVs,as the superpowers,without giving much thought to the strategic implications. Some scholars have explained such trajectories as technological determinism: if a state can build it,it will try to do so,whether the technology fulfils a particular requirement or not.
Unfortunately,if this is the case,DRDOs pursuit of its own prestige may upset Asian strategic stability by triggering concerns in Beijing and Islamabad that Indias nuclear posture is no longer one of assured retaliation but one of nuclear superiority that threatens the survivability of Chinas and Pakistans nuclear forces. Such fears might force them to re-evaluate their nuclear requirements and rapidly expand their nuclear arsenals to make any disarming attempt by MIRVd Indian missiles impossible. While China has historically been relaxed about this possibility,Pakistani nuclear planners have suggested publicly that they account for possible first strikes in how they size and deploy their nuclear arsenal. It may push China and Pakistan toward more dangerous postures emphasising preemptive launches,since they might fear that their nuclear forces face a use them or lose them dilemma in a potential crisis. This is incredibly destabilising.
The second possibility is that India has quietly decided to abandon its nuclear posture of assured retaliation and no first use in favour of seeking nuclear superiority,and that deploying MIRVs and missile defences are,in fact,government policy. Since all public signals continue to point to an assured retaliation strategy and continued reaffirmation of the no first use pledge,this is unlikely.
The third explanation is that the government may approve the development of MIRVs,but in order to enhance the survivability of Indias second-strike deterrent. If Indias civilian nuclear managers and Strategic Force Command maintain warheads separate from missiles,and anticipate that an adversary may try to target Agnis in a conflict to degrade Indias nuclear retaliatory capability,MIRVs enable one to retain sufficient retaliatory throw-weight even with a few surviving missiles. Suppose India has 100 nuclear warheads and 100 various Agnis in its future force posture. If three-fourths of the Agni force is disabled by strikes,the remaining 25 Agnis with multiple warheads can achieve the same retaliatory throw-weight as a full complement of single-warhead Agnis. Such a strategy is not entirely irrational,assuming India believes its warheads are survivable but its missile force will be small or vulnerable.
If this is indeed the strategy,the problem lies in convincing China and Pakistan that Indias MIRVs,and potential missile defences,are defensive rather than offensive. If so,the government should clarify exactly how deploying these capabilities are consistent with its longstanding strategy of assured retaliation. A MIRVd sea-based force makes a lot of sense for an assured retaliation strategy. But the argument for a MIRVd land-based force is harder to make. Especially since,at first glance,dispersed single-warhead missiles seem more stable than a MIRVd force for an assured retaliation strategy: it optimises survivability by requiring an adversary to hit many more targets to disarm your force,still assures the ability to inflict massive damage,and minimises incentives to be struck first since it does not pose a disarming threat to the adversary.
India finds itself in a strategically awkward position: advertising the development of a potentially destabilising capability that it does not yet possess and for which it has not yet articulated a clear rationale. If the government does not envision a role for MIRVs,it should enforce greater discipline on DRDO messaging. Alternatively,if there is a clear role for MIRVs,it should articulate it publicly to alleviate Chinese and Pakistani fears of a tectonic shift in Indian nuclear strategy. Developing capability without a strategy is a recipe for disaster. There are both malign and benign explanations for developing MIRVs and missile defences. In this case,there is virtue in the government being transparent about its intended course,lest Asia quickly find itself in an unnecessary and dangerous nuclear arms race.
Vipin Narang teaches political science at MIT. Christopher Clary is a PhD candidate in political science at MIT