Does it really need a nuclear capability?

“Within days,” Air Force Assistant Secretary Bill LaPlante told us at the beginning of the week, but we’re still awaiting that RFP on the LRS-B. So, I continue to prematurely work through the four questions that I believe policymakers should want answered if the program is to proceed. To recap from yesterday, those are

  1. If the bomber is to have a conventional capability, how it is going to penetrate serious air defenses?
  2. If the bomber is to have a conventional capability, why is a shorter-ranged aircraft inadequate?
  3. If the bomber is to have a nuclear capability, why are ballistic missiles are inadequate for nuclear attack?
  4. Can the performance requested be provided within the cost and schedule advertised?

Here goes number 3.

Competition with ballistic missiles may finally have gotten some serious attention inside the USAF, as several generals have suggested that the bomber be built without nuclear capability, at least initially. Eliminating the immediate requirement would, after all, save at least a little money.

Is this wise? As Ben Friedman, Chris Preble and Matt Fay of the Cato Institute argue in their recent paper  The End of OverkillReassessing U.S. Nuclear Weapons Policy (Cato Institute, 2013), a nuclear-armed bomber force hardly contributes at all to deterring a large nuclear attack. A similar argument was made a few years ago in Dana Johnson, Christopher Bowie, and Robert Haffa’s Triad, Dyad, or Modad? Shaping the US Nuclear Force for the Future (Mitchell Institute for Airpower Studies, 2009), which called for the denuclearization of the B-52 fleet. At any given time, almost all the American long-range bombers are on five airfields, whose locations have been known precisely for decades. That’s several fewer aim points than for the ballistic missile submarine fleet. If eight of the Trident submarines are at sea at any given time, then the fleet comprises ten aim points, but most importantly, only those of the two submarine bases (at Bangor and King’s Bay) are known for sure. If the Minuteman force has a relative advantage beyond its low operating cost, it’s the multiplicity of aim points it presents any attacker.

Today, the question of the ballistic missiles’ utility is further addressed by the state of missile defenses: they just don’t work well. As David Willman’s article in the Los Angeles Times last weekend made clear, the most ambitious system anywhere in the world—the US Army’s Ground-based Midcourse Defense (GMD) system—has had a success rate of less than 50 percent over the past fifteen years. At that rate, the firing protocol might call for a four-missile salvo against any incoming round, just to insure a high probability of interception. Phil Coyle, the former Pentagon weapons testing chief, thinks that this is a reason to junk the system. I once separately heard the argument that a 50 percent probability is worth the investment. Can anyone imagine the cost avoidance if an interceptor actually does connect with an accurately-aimed incoming nuke?

Even so, that approach will only work against small incoming salvos. The US so far has only 30 interceptors at two sites (Vandenberg and Fort Greely), though Defense Secretary Hagel does want to add another 14. That could be a reasonable defense against a small salvo from Iran or North Korea, but not a barrage from Russia or China. But turn the problem around, and the rationale for US bombers with nuclear weapons looks weak. Presuming that Russian or Chinese defense are less impressive, then what’s the point of fielding a different delivery system? What are the bombers a hedge against?

Other than sentimentality, at least one feature keeps keeps nuclear bombers in business: the ability, within a short redeployment time, to precisely drop a low-yield nuclear weapon anywhere in the world. Ballistic missiles cannot always do that. Indeed, the Minutemen on the Great Plains are particularly constrained in the target sets. Even when the morale at the missile bases is good, sending a flaming datum onto a suborbital trajectory can induce unwanted anxiety in third parties not necessarily subject to the just-starting nuclear war at hand. Bombers can undertake that limited nuclear strike mission without such geographical constraints.

So, if the RFP calls for nuclear munitions, ask under what scenarios that capability would be essential. But if the RFP calls for only conventional capabilities, ask what the effect on American nuclear strategy might be. Either way, there’s an important trade to be made.

James Hasik is a senior fellow in the Brent Scowcroft Center on International Security.