Secretary of Defense Panetta has sent a heartburn letter to Senators John McCain and Lindsay Graham that outlines a series of cuts to the US nuclear force that may occur under sequestration.  Speaking about the totality of cuts — not just the nuclear ones — Panetta warned that sequestration would have “devastating effects.”

It is an interesting intellectual exercise to imagine “deterrence under sequestration.”  From simply the standpoint of nuclear deterrence, how bad would sequestration be?

Let’s be clear — this is not an argument either for or against sequestration.  It is possible, as Dov Zakheim argues, that sequestration may actually result in smaller cuts to the defense budget.  And, of course, Panetta’s letter lists “decisions relating to major programs” that could occur.  Could. In English, “could” does not mean “will” occur.  In some contexts, could does not even mean “likely” to occur.

I just want to ask a simple question.  Let’s take Panetta’s list as a challenging worst-case scenario for US defense planners.  Here are the major decisions that Panetta could take under sequestration.  Let’s assume he makes them all:

* Terminate Joint Strike Fighter; minimal life extensions and upgrades to existing forces ($80B);
* Terminate bomber; restart new program in mid 2020s ($18B);
* Delay next generation ballistic missile submarine; cut force to 10 subs ($7B);
* Eliminate ICBM leg of Triad ($8B).

Now, the Department of Energy surely has a similar list, but Steven Chu didn’t send a heartburn letter over to the Hill, so I am not privy to it.  Let’s assume DOE simply makes cuts that mirror this list, with the elimination of lifetime extension programs for any warheads with no means of delivery, and appropriate numerical reductions elsewhere.  What does our sequestration deterrent look like?

Strategic Forces Under Sequestration

Let’s start with a baseline – the projected US nuclear deterrent under New START.

Based on the recommendations of the Joint Chiefs of Staff, we plan to meet the Treaty’s limits by retaining a triad of up to 420 ICBMs, 14 submarines carrying up to 240 SLBMs, and up to 60 nuclear capable bombers.

Assuming that we apply Panetta’s decisions to this baseline, the resulting deterrent force comprises 10 ballistic missile submarines, 60 nuclear capable bombers and no intercontinental ballistic missiles (ICBMs).  As existing nuclear-capable fighter aircraft age, the US eliminates its forward-deployed “tactical” nuclear forces.

A fully uploaded sequestration deterrent could (there is that word again) comprise as many as 2,672 operationally deployed nuclear weapons.  Using the New START counting rules — which count all heavy bombers as one warhead despite an ability to carry between 8 and 20 nuclear weapons — the resulting force could total 1,596 nuclear weapons.

New START, Not  A Problem.

The first thing that immediately jumps out is that we would have no trouble staying at New START levels of 1550 warheads.  This is slightly different than the New START force, since there is no reason to eliminate SSBN tubes with a smaller force and I have assumed we load more warheads on each Trident D5 missile.

The total number of US delivery vehicles, on the other hand, would be 252/300 — far below the New START limit of 700/800. (New START has separate limits for deployed and non-deployed missiles and bombers.) Russia, too, will drift far below 700/800 delivery vehicles, though probably not much below 500.

The US was the party that sought a higher number of delivery vehicles in New START to accommodate a force structure that it now appears we cannot afford. During the New START process, I argued that “there is, or ought to be, a dictum that, in arms control, the shoe ends up on the other foot. You live to regret the concessions you achieve.”  The US got the higher delivery vehicle number, at the cost of a higher number of warheads.  If sequestration reduces the number of US delivery vehicles by 400 or so, this will be an instance of Lewis’s dictum.

Essentially, sequestration means that the Pentagon needs to move 400 warheads to sea on a slightly smaller number of SSBNs.  To put this in perspective, if the US were to agree to another round of nuclear reductions with Russia within the parameters floating around Washington, the result would look a lot like a sequestration deterrent.

I’ll be honest.  That sort of surprised me.

Sequestration Means Policy Change

A sequestration deterrent would, however, represent a sharp break from past policy in certain areas.  I suspect that discontinuity would be lost on anyone not steeped in the arcana of the subject.  To anyone else, 1550 is a significant number of nuclear weapons.  Still, I would notice the difference.

First, and perhaps most important to me, 10 SSBNs is probably not enough to keep two SSBNs at sea in each ocean continuously, especially if the missiles are fully-loaded.  (The issue here is target coverage.  A fully loaded missile has a shorter-range, so the submarine must travel further to station.) The result would probably be a 2-1 configuration, with the other 5 or 6 boats in transit.  To a first approximation, some targets in central Russia would not be covered by a non-generated force on a day-to-day basis.

Second, eliminating the ICBM leg of the triad sacrifices promptness of response. Clark Murdock and now-USD(P) Michelle Flournoy, in the old CSIS report Revitalizing the US Nuclear Deterrent, rejected an SSBN/Bomber dyad on the basis of “extreme insufficiencies in promptness (because it includes no ICBMs) and in robustness.”  That was a jargony way of saying only ICBMs can hit targets within an hour, because it can take a while to communicate with submarines at sea.  (Side note: It may sound strange, but some people worry about survivability of an SSBN/Bomber dyad because ICBM silos are warhead sinks while submarines in port and bombers off alert are vulnerable.)

Third, extended deterrence — at least the nuclear flavor — would cease to rely on dual-capable aircraft (since any F-35s will not be nuclear capable).  Instead, as the US and its allies retire their fleets of F-16 and Tornado aircraft, U.S. policymakers must find new ways to credibly extend nuclear deterrence from the remaining central strategic forces.

These may not sound like big changes, but each is far more consequential than any decision in the 2010 Nuclear Posture Review.  Really.  No, really.  Stop laughing. Please.

Deterrence Under Sequestration

These are major policy decisions that, in normal circumstances, would not be taken lightly. (I am not kidding.) Speaking for myself, I would probably only freely choose to cancel the program to make nuclear-capable the F-35.  Under duress? I think I could live with a smaller SSBN force that, on a day-to-day basis, did not completely cover targets in the deepest Russian hinterland.  I could also live without the promptness provided by ICBMs, especially if Panetta finds preserves some of the investment in prompt conventional strike capabilities.

Obviously, if either capability were free, that would be awesome.  But this is a time of hard choices.  Neither capability is so valuable that I would argue such cuts should be borne by other defense programs or by domestic programs. Deterrence under sequestration is not ideal.  But I’d rather do that than, say, cut  social security or medicare benefits to senior citizens.  Those are real costs suffered by real people.  These capabilities are insurance that are nice to have.

Don’t get me wrong, sequestration is a dumb way to reduce the nuclear force. (It would have been better to negotiate these reductions with Russia, for instance.)  But it isn’t clear to me it is a particularly dangerous way to do it.