I have my semi-weekly column up at Foreign Policy arguing that the impending demise of Nunn-Lugar is of a piece with the loss of monitoring at Votkinsk and obligatory telemetry exchanges with the expiration of the START treaty.  The Russians want us out as they modernize.

I worry that the bilateral arms control process is dying a slow death in large part because we’ve failed to expand it beyond reductions into a broader set of measures to strengthen strategic stability.  In particular, as I’ve been arguing for some time, I think the Russians are much more worried about decapitation — the prospect that they could not command their nuclear forces following an attack and would be unable to retaliate.  I’ve pestered my friends, enemies and people I don’t even know with the odd idea that this Russian fear might account for a series of weird things they’ve said and done, including expressing concern about nuclear-armed missile defense interceptors in Poland.

How do we start talking about command and control with Russia, especially if the Russians won’t address the matter directly?  I would propose that the US and Russian agree to a joint statement prohibiting the placing of nuclear weapons on missile defense interceptors.  It is a modest measure that begins, obliquely, to address Russian concerns while strengthening stability.

The full proposal is after the jump.

Prohibiting Nuclear Armed Missile Defense Interceptors

The United States should propose, as a part of any dialogue on missile defense cooperation, that Russia also prohibit nuclear-armed ballistic missile defenses. This could be codified in a Joint Statement of a ten-year duration signed by both Presidents.

This should be a relatively easy proposal for the United States to accept. Such an agreement would not further constrain the US Missile Defense Agency. US missile defenses rely on “hit to kill” intercept technology and are not nuclear-armed.  The Stevens-Feinstein Amendment prohibits the Defense Department from spending on the “research, development, test, evaluation, procurement, or deployment of nuclear armed interceptors of a missile defense system.”

The Russians might be less interested.  As best I can tell, the Moscow ABM defense system still relies on nuclear warheads.  There are some reports that Russia is arming the S-400 and S-500 with nuclear weapons, though I don’t know how much credence to give them.  There is also some evidence that the Russians might be interested in moving to a conventional missile defense around Moscow.  After I and a colleague floated the idea a few years back, Sergey Rogov told the 2011 Carnegie Nuclear Policy Conference that Russia might eliminate the nuclear-armed ABM system around Moscow, but his asking price was a bit high.  (Rogov told some of my colleagues he wanted the US to share SM-3 interceptors with Russia to help with the transition to conventional missile defenses.)

Still, the US and Russia have to talk about so-called “nonstrategic” nuclear warheads at some point — and this is probably the easiest basket to start with.

A Joint Statement would codify the US prohibition and permit basic confidence-building measures, such as exhibitions and complementary visits, that could take place in the context of broader missile defense cooperation.  The Russians might value related confidence building measures regarding US missile defenses in Europe and some limited technical cooperation involving radars.

An agreement to prohibit nuclear-armed ABM interceptors would provide at least two benefits.  First, a prohibition on nuclear-armed missile defense interceptors would provide a mechanism to address the least difficult portion of Russia’s stockpile of tactical nuclear weapons.  These weapons are obsolete, making them an excellent target for elimination.  (The Joint Statement might also commit the parties to specific forms of missile defense cooperation that allow Moscow to replace its nuclear-armed missile defense system around Moscow.)

The Moscow ABM system really bothers me from a stability perspective. The system is nuclear-armed.  It is kept off alert in peacetime, but the Russians plan to place it on alert during a crisis. As a result, the Russian military will be operating the system in an unfamiliar fashion during an extraordinarily tense environment in which an attack is believed likely.  Furthermore, the decision to use an ABM interceptor must be made under the most dire time constraints and is, therefore, pre-delegated, possibly with the decision to alert.  Even the US has experienced accidental ABM launches with theater systems.  It is not clear to me that, if a nuclear-armed interceptor were used over Moscow against a flock of geese, that the Russian command-and-control system would understand it was one of their own or survive the EMP effects.  Then all hell might break loose. I’d like to get rid of this thing.

Second, a prohibition on nuclear-armed missile defense interceptors would enhance strategic stability by reinforcing the prohibition on intermediate-range nuclear forces.  Some existing missile defense interceptors exceed MTCR thresholds.  Some planned versions may exceed INF treaty thresholds, which is bad news for a treaty that doesn’t need more bad news.  A while back, I asked David Wright to do a basic calculation and he concluded that alow-speed SM-3 Block II (4.5 km/s burnout) could reach Moscow from Poland with a 200 kg payload, and the high-speed Block II (5.5 km/s burnout) could reach Moscow from either Poland or Romania with a 200 kg payload. A ban on nuclear-armed ABM interceptors, combined with some confidence-building measures, might make the difference in preserving INF.