Wednesday, June 10, 2015

IRBMs in the A2/AD Scenario

In the previous post, a reader brought up the possibility of Intermediate Range Ballistic Missiles (IRBM) as an A2/AD weapon.  I had considered mentioning them, specifically, in the post but opted not to because I feared they would bog the discussion down and obscure the more general topic.  However, now that it’s been brought up, let’s look a bit closer at IRBMs in the context of A2/AD.

The Chinese, of course, have developed IRBMs for various uses including the so called “carrier killer”, the DF-21.  This IRBM has generated much press coverage due to its combination of lethality and survivability.  A ballistic missile is a difficult weapon to counter.  Indeed, the USN is expending a great deal of money and effort in the attempt to defend against these weapons.  The entire Burke class is being modified to counter ballistic missiles.  Lethality and survivability are two of the characteristics that would be highly useful in an A2/AD penetration scenario.  Thus, a US IRBM would seem to meet the needs for a weapon with extremely long range, massive destructive ability, and survivability.

Of course, this immediately brings up the first objection to the use of IRBMs and that is the possibility of misinterpreting a conventional ballistic missile as a nuclear strike missile.  I’ll pause a moment, now, to allow some of you to finish wailing, gnashing your teeth, and wringing your hands in hysteria.  I can hear you saying we can’t use an IRBM – the Chinese would assume we were launching a nuclear attack and it would mean instant nuclear Armageddon.

Take a deep breath … 

OK, you did note the previous paragraph where we noted that the Chinese have already developed their own IRBMs and, apparently, have every intention of using them.  They, clearly, aren’t worried about us misinterpreting their usage so why should we worry about their reaction?  Well, some would answer that their missiles are incapable of reaching the US and so could not be a nuclear threat to us whereas ours could reach their soil and could constitute a nuclear threat.  Hogwash!  First, their missiles can reach US carriers which are sovereign US territory and they can reach bases such as Guam which, again, are US territories.  Second, if the Chinese are that concerned about nuclear misinterpretation, all they have to do is enter into an agreement with the US to ban IRBMs – clearly they have no concerns.  So, there is no problem with using IRBMs.

Moving on …

What platform would launch an IRBM?  Two candidates come to mind.  One is the submarine with it’s attendant benefits of survivability and stealth and the other is a surface ship with either the newer and larger Mk57 VLS (currently only installed on the Zumwalt, as I recall) or a new, purpose built launch system, presumably a VLS variant similar to an SSBN launch tube. 

The Mk57 VLS is a larger version of the venerable Mk41 and is intended to accommodate future, larger missiles.  The canister is around 23 ft long and 28 inches in diameter and can support around a 9000 pound load.  Whether this is sufficient to house an IRBM developed for the A2/AD scenario, I don’t know.  Remember, a 1000-2000 mile conventional IRBM is probably a significantly different beast from an ICBM.  Can we build one to fit existing VLS systems?  I don’t know.

Cost is an issue and I have no idea what the cost of a suitable tactical IRBM would be and, thus, what the cost-value relationship would be.

Numbers are also an issue and are closely related to cost.  Can we build enough missiles to be effective?  Presumably, these missiles would be tasked with destruction of fixed, high value targets.  How many such targets are there and how many missiles would be required for their destruction?  Again, I don’t know.

It would seem that IRBMs offer a partial solution to the A2/AD penetration requirement, at least in theory.  Whether we could build them in sufficient numbers and come up with a suitable launch system is an open question although nothing I’ve read suggests we couldn’t.  Certainly, the very characteristics of lethality and survivability that make defending against an IRBM such a headache for the Navy suggest that they would make an effective offensive weapon against an A2/AD zone.


  1. I do not believe that the IRBM is as big a threat as some people make it out to be. The V2 for example suffered from cost as well. So you cannot have that many - or if you do there's a big opportunity cost.

    The issue is that you still have to find the carrier group and steer the IRBM accurately (it's very hard to steer a ballistic missile at those velocities - ICBMs historically were used mostly to target fixed bases, which is why submarines were so dangerous).

    That is not to say that carriers are not in deep danger. Submarines, better anti-ship missiles, and other weapons are making very rapid advancements. The other is that the aircraft the USN uses are short-legged compared to the what the competition has.

    Fixed airfields is another matter and even a miss that craters part of an airfield could render it not usable, which during a war is critical.

    The other question I have is, if you are planning to launch IRBMs back, what targets are you planning? It would have to be very high value indeed.

    1. Alt, note that I've focused this discussion on our use of IRBMs as A2/AD penetration aids. Your points about the use of IRBMs against mobile targets (carriers) are quite valid, of course.

      Regarding your question about what targets would be assigned IRBMs, it would be high value, fixed targets that contribute to the defense of the A2/AD zone. So, airbases, IRBM launch sites, naval bases, fuel storage locations, submarine "pens", mine storage locations, etc.

    2. You would need a lot of IRBMs to do it though - China has a lot of airfields and they are often underground (and more heavily protected) than American airfields.

      I suspect that China will have more in the coming decades.

    3. Depends all on strategy. You don't necessarily need to destroy the bunkers, littering the actual runways with mines would just as quickly shutdown the airbase.

  2. There shouldn't be any technical reason why SSBN class missile launchers couldn't be mounted in launcher groups aboard a surface vessel.

    Who cares what it costs. Build a hundred fewer F-35's. The bigger questions are, what should the surface vessel (or vessels) look like, what kinds of missiles are allowed to be carried in the launchers, and what doctrines and policy apply to their use?

    1. The last part of your question, essentially asking about ROE, is quite pertinent. It does no good to build IRBMs and associated ship/sub launch platforms and then balk at using them. We need to establish,

      1. The willingness to use them and,
      2. The conditions under which we will use them along with a candidate target list.

      Having committed to the first, the conditions for use will devolve to simple tactical considerations. When a suitable tactical advantage can be gained ... launch.

  3. For once I an going to agree with you, the USN could should the Tactical IRBM as part of an A2/AD fight. The only limitations I see is any existing arms control treaty. Still It should be possible to build missile with a range of 300 miles that can fit into a MK57 launcher crate. One Thing I would avoid would be going for extended range or large payloads. Keep It Simple Stupid should be our guiding principle in developing such a weapon.

  4. I'm sorry CNO, but there's a fundamental difference between watching a group of ballistic missile arc towards a CVBG or Guam and watching them arc towards San Francisco or Beijing.

    The former would trigger war, the later could trigger nuclear Armageddon.

    IRBMs are especially tricky due to their short time of flight. Political leaders might only have 10-15 minutes to decide if they should launch a full nuclear retaliatory attack or not.

    Here are two background documents on conventional ballistic missiles that go into greater depth:

    1. Smitty,

      The Chinese are planning to fire DF-21 missiles at U.S. and allied forces in the 1st island chain: how is the problem any different?

      How do the Chinese expect us to differentiate between a anti-ship DF-21D and a nuclear DF-21C?


    2. Firing nukes at deployed forces and allies is a whole lot different than firing them at one's home country.

      If we fire off a bunch of SLBMs at the Chinese mainland, how do the Chinese know if they are conventional tipped, aimed at hitting pinpoint targets, or nuclear tipped, aimed at turning China into a radioactive slag?

      They have to make a quick decision whether to launch a full nuclear retaliation or not.

      The Chinese firing ballistic missiles at our deployed and allied forces is not an existential threat to us.

      Us firing ballistic missiles, that can't be differentiated between conventional and nuclear, at their homeland is an existential threat to them.

    3. Smitty, so you're OK with China lobbing nukes at our territories, bases, and forces while we unilaterally limit ourselves to conventional weapons? Now that's fighting with one hand tied behind your back!

    4. CNO, come now. ;)

      "Existential threat".

      Lobbing ballistic missiles at the Chinese homeland is a threat to their very existence!

      A Chinese premiere sitting in a bunker may only have ten minutes before he is engulfed in a nuclear fireball to decide if he should launch a full nuclear retaliatory attack.

      A US President sitting in the war room can wait out an attack on US territories and bases. If it's nuclear, he/she can respond in kind. It is NOT an existential threat.

    5. Smitty, do you seriously believe that the US will allow China to lob nukes at us without retaliating in kind? This is the basis of the old MAD doctrine. The onus to avoid nuclear conflict lies just as much with China as us. If China doesn't want to have to deal with incoming IRBMs then they need to curtail their own IRBM program.

    6. "A US President sitting in the war room can wait out an attack on US territories and bases. If it's nuclear, he/she can respond in kind. It is NOT an existential threat."

    7. Again, so you propose ignoring an entire class of potentially highly effective weapons because China might be worried about them?! I think the point of weapon systems is to cause the other side to worry. Again, if China feels the risk is too great they have only to curtail their own IRBM program.

      We're going to have to leave this one as a disagreement.

    8. Actually, no. I'm not against them. I just think there are some very real operational concerns in using them against a nuclear armed state.

      Of course attacking a nuclear armed state in general runs a serious risk of escalation.

  5. For info: The Pershing II of 1980s vintage weighed @16500lbs, was almost 35 feet long, 40 inches in diameter, carried a 880 lb "dial-a-yield" nuclear warhead and had a range of 1100 miles. Might be some engineering challenges fitting a useful IRBM in a Mk 57 VLS

  6. The ATACMS MGM-168 is 24 inches in diameter, 13 feet long, and carries a 500 lb unitary warhead. It has a range of 300 km to stay within the limits of the MTCR.

    A booster or a longer first stage could easily carry a 1,000 lb warhead 300 km.

    1. And its highly likely that the existing 300km is not a real technical limitation as well. Given an almost 2x increase in length, it should be possible to do a 500kg warhead with a range >>300km.

  7. Okay.

    I agree in part and dissent in part.

    I agree in the sense that we have to do something to at least have the ability to deter the Chinese; and that our previous discussion involving cruise missiles launched against the A2/AD isn't that much different in terms of scary scenarios (150 nuclear capable TLAMS heading your way is a plenty scary way of poking the nuclear bear, IMHO).

    That said... IRBM's seem to be an especially useful, and for that reason, especially scary weapon.

    Especially when we are dealing with a CCP politburo that is kind of riding the capitalist tiger and is a bit jealous and scared for its power to begin with.

    IMHO, yes, we should build them. Maybe modify something for the SSGN's or the Block III Virginia's, which IIRC has a bigger VLS diameter...

    but at the same time we should start talks with the Chinese to ban IRBM's. Yes, they lose a potential huge weapon with the DF21... but they also lose alot of risk if we have something there.

    Just my $0.02

  8. As the village idiot who keeps beating the ballistic missile drum; a few points:
    1. The ideal range for a U.S. MRBM or IRBM is 1,200-1,500nm – a map and compass will demonstrate the utility of this range.
    2. The missile would ideally be capable of launch from a Virginia payload module.
    3. The Pershing II is a good place holder for the desired size and capability – obviously it would have to be navalized, and its svelte length and girth adjusted, but it sets a good bench mark.
    4. A unitary explosive warhead is probably the *least* useful warhead for the mission, and probably not needed – at Mach 8+ the kinetic energy from the impact of this weapon would be awesome. Suitable warheads for the missile would be: 1) area effect (could be bomblets, or cubicle shaped ceramics), and 2) an armor piercing or concrete penetrating warhead for bunker busting.
    5. The missile should be employed not just by naval forces but also the army in the form of mobile launches (again, the MGM-31 sets the bench mark). Even a dozen batteries would greatly complicate the strategic planning of NK and the PRC; which is exactly what we want a weapon like this to do.


    1. A good defense suppression warhead would be a load of guided antiradar submunitions. For real fun set off 10,000 ft. above an AEW aircraft's orbit.

    2. We can't put them on land-based launchers without violating the INF treaty.

      I'm not sure an inert warhead would be good enough for destroying deeply buried targets. Penetrating bombs rely on generating sufficient overpressure, generated by HE, in confined areas to destroy whatever is in them. I'm not sure inert warheads would do the same. Maybe they would.

    3. Correct me if I'm wrong but China is not a signatory to the INF treaty, are they?

      China also does not have much of a reputation for honoring treaties which makes one wonder why we would go out of our way to honor a treaty benefiting them and to which they are not a party?

    4. Russia is a signatory. We honor the treaty to keep Russia from developing intermediate ranged nuclear weapons.

    5. "I'm not sure an inert warhead would be good enough for destroying deeply buried targets. Penetrating bombs rely on generating sufficient overpressure, generated by HE, in confined areas to destroy whatever is in them. I'm not sure inert warheads would do the same. Maybe they would."

      I am not sure where the concept of an "inert warhead" came from: I said that a "unitary explosive warhead" was the least useful.

      That said, a 1,000 kg metal shell moving at Mach 8+ speeds would be a devastating weapon, rivaling a small nuclear device in destructiveness.

      The CRS report you cited mentioned the effectiveness.


    6. "Russia is a signatory. We honor the treaty to keep Russia from developing intermediate ranged nuclear weapons."

      First, the treaty was between the US and USSR. With the collapse of the Soviet Union, it is highly debatable that the treaty remains legally in force. Russia was not a signatory. The US has unilaterally opted to act as if Russia was a signatory.

      Second, Russia has already violated the treaty (and we may have also) and declared the treaty void, stating that it was not in their best interests.

    7. "First, the treaty was between the US and USSR. With the collapse of the Soviet Union, it is highly debatable that the treaty remains legally in force. Russia was not a signatory. The US has unilaterally opted to act as if Russia was a signatory."

      Russia is widely regarded as the legal successor of the USSR. As such, it remains signatory of a lot of treaties, including the INF one.

  9. The nuclear misidentification problem has been solved by the Advanced Hypersonic Weapon program. It uses a glide body rather than a traditional ballistic warhead, this gives it a vastly different radar signature.

    1. Midgetman, you're right that the AHW has a different flight profile and radar signature. On the other hand, there's nothing that would prevent us (or the Chinese who are also developing a AHW) from putting a nuclear warhead on an AHW or a cruise missile (as has been done). Thus, the mere fact that an incoming missile is not a ballistic missile does not mean that it isn't nuclear armed.

      The only real "protection" against nuclear missiles is some form of MAD.