Joshua PollackThe Range of North Korean ICBMs

If there’s one thing in the public discussion of proliferation that troubles me the most, it might be this: the systematic minimization of North Korea’s nuclear and missile capabilities in the American news media. Someone could write a book on this phenomenon and its causes, but life is short. Let’s just focus on just one question for now: how far can North Korean ICBMs fly? 

News reports persistently describe North Korea’s three-stage space launcher, the Taepodong-2 (TD-2), as capable of delivering a reasonably sized warhead to Alaska or maybe to the western continental United States. But at least if we go by the official, unclassified, publicly released estimate of the U.S. government, that’s wrong! The TD-2 can range all of the USA, from sea to shining sea.

Here it is in black-and-white from the National Intelligence Council’s September 1999 paper, “Foreign Missile Developments and the Ballistic Missile Threat to the United States Through 2015”:

“A two-stage Taepo Dong-2 could deliver a several-hundred kilogram payload to Alaska and Hawaii, and a lighter payload to the western half of the United States. A three-stage Taepo Dong-2 could deliver a several-hundred kilogram payload anywhere in the United States.”

Emphasis added, so nobody misses the point.

This many-handed estimate reflects the bygone debates of the 1990s. Initially, it seems, the TD-2 and little brother, the Taepodong-1 (TD-1), were thought to have two stages each. When the TD-1 took flight in August 1998, lo and behold, it had three stages. That forced a reconsideration of what the TD-2 might look like, with the results you see above.

When the TD-2 ultimately materialized—flying in July 2006, April 2009, April 2012, December 2012, and February 2016, the last two times successfully—it had three stages. (We’ve never seen pictures of the 2006 version; at least one news report said it had only two stages.) For whatever reasons, though, reporters have mostly gravitated to estimates associated with a two-stage version of what turns out to be a bigger rocket. And the more often these estimates are repeated, the more the confusion is reinforced.

It probably doesn’t help that the U.S. government no longer spells out these sorts of estimates. Anonymous officials ascribed this choice back in May to both the bad aftertaste of the Iraq WMD debacle and what reporters called “an effort to avoid strengthening and encouraging Mr. Kim.”  The U.S. Air Force’s National Air and Space Intelligence Center does periodically release a document on missile threats, but it coyly offers a range of “5,500+” km for the TD-2, alluding to the lower bound of what defines an ICBM.

Lest this silence engender any doubts—has that 1999 estimate changed, perhaps?—after this February’s launch, the semi-official South Korean news agency described the TD-2 as having a range of 12,000 km if used as a missile.  Give or take a kilometer or two, that’s the distance from North Korea’s east-coast launch site to downtown Miami. Hey, Puerto Rico is safe, at least!

And what about North Korea’s mobile ICBM, the KN-08, which it has displayed a number of times since 2012, but it has yet to fly, or its apparent successor, the KN-14?

We don’t know much about the KN-14, but in testimony this April before the Strategic Forces subcommittee of the House Armed Services Committee, Admiral William Gortney, the commander of US Northern Command, was faced with this exact question about the KN-08. Asked whether he assumed that the KN-08 could target any point in the continental United States, he responded in the affirmative. South Korean media reports agree, ascribing a 12,000 km range to the KN-08—the same as the TD-2.

The North Koreans certainly haven’t been shy about their ambition to hang a nuclear Sword of Damocles over spots 11,000 km or so away. Lately, they’ve also tried to put to rest any doubts that the KN-08 is a real missile.

Before anyone objects: all the usual caveats apply. ADM Gortney, in his testimony, assigned a low probability to the idea that the KN-08 could perform successfully, a reasonable comment about a missile that has yet to be flight-tested. But now that the North Koreans have enjoyed their first successes in flight-testing an intermediate-range ballistic missile and a two-stage, solid-fueled submarine-launched ballistic missile, a KN-08 flight-testing campaign seems like a logical next step. Stay tuned.

Obviously, too, what the government says isn’t the last word. Experts are free to devise their own estimates. And none of this discussion is intended as a comment on the wisdom or efficacy of missile-defense programs, which is a topic for another day. (Here’s what I wrote a few years ago.) But just for clarity’s sake, it would be helpful for our reporters to pause before recycling what so many have already written so often. Instead, they might be well advised to start fresh. And a fresh assessment could start by considering what official sources in Washington have had to say.


  1. Xu Tianran (History)

    In early 2016 Yonhap quoted a SK official as saying: “North is presumed to be in possession of a long-range missile with a maximum range of 12,000 kilometers with the capacity to carry a payload weighing about 250 kg.”

    This is consistent with the previous estimate in 2013 that the rocket can deliver 500-600 kg warhead to over 10,000 km. However, some media quoted 12,000 km as maximum range without mentioning the pre-condition of 250kg payload, which is for now pretty unlikely. So Unha would probably has a range of 8,000-9,000 km range with a 600-700 kg warhead if used as an ICBM.

    Another thought: Unha has many shortcomings as an ICBM and it seems too big to deploy without a silo. However, I found that Unha’s size is only 2 meters longer, and 15 cm wider than the Chinese DF-4 mid-range missile (28 m long, 2.25m diameter) . So classic deployment mode of DF-4 should apply to Unha as well, namely in-cave storage and out-of cave erection and fuelling. Chinese believed that this method was better than silos. In this regard, a low-tech Unha might actually be the regime’s emergency-use ICBM though they never flight tested a ICBM RV. Now they can build a better Unha with the powerful HS-10/Musudan as 2nd stage, it would be shorter than DF-4 and cheaper, more reliable than the brand new KN-08/14.

  2. Joshua Pollack (History)

    Thanks for pointing that out. But as best as I can tell, either the unnamed official (paraphrased in the story, not quoted) or the reporter seems to have been conflating the estimated mass of the KMS-4 satellite with the presumed mass of an ICBM payload.

  3. E. Parris (History)

    Judging from what we know about North Korean offensive missile development, the US still has a window of opportunity to intervene. But that window appears to be closing rapidly. The North Korean regime must be overthrown, and that task should be performed by South Korea in conjunction with the US military. We have watched the buildup of nuclear missile inventories in both the USSR and China. It is best to take care of the North Korean tangle as soon as possible. This will be an unpleasant task that will challenge the leadership capabilities of this nation. But it must be done.

    • Joshua Pollack (History)

      It’s not gonna happen. Even if we thought we could handle the TD-2 and the KN-08 in whatever states they exist today, what about Seoul? What about Tokyo? I’m afraid it’s much too late for this conversation.

    • Mark Hayden (History)

      The DPRK had been reduced to rubble by US bombing in Korean conflict. Almost 30 percent casualties and almost every building in DPRK was destroyed. But the DPRK constitution in part written by Stalin continued to be the law of DPRK . The DPRK knew that if became to much of a threat the USA would massively bomb it again. Despite the risks the DPRK goal was to have nuclear arsenal to defend themselves against attack and punish an attack if one occurred again. However the very process of acquiring adequate fissile material and delivery systems could have precipitated a attack by nuclear armed USA. If USA saw DPRK as a potential nuclear power without enough ‘full fledged nuclear” destructive power the USA would be tempted to attack. The DPRK was almost bombed when its puny rector began put out small amounts fissile material. DPRK completed its path to nuclear power as rapidly as possible to prevent an attack. For DPRK more nukes and better delivery systems meant deterrence and safety . The nuclear testing of DPRK is at least ten years old. Pakistan tested 6 nukes and has 130 plus nukes within a decade of testing its first nuke. Likely the DPRK nuclear stockpile is over 100 already well on its way to 500. Estimates of its warheads range from twenty to hundreds.After fifth test the DPRK claimed it can produce as many nuclear warheads as it wanted . Russia wants capability to deliver 1500 plus warheads with thousands in reserve. Why should DPRK want less?
      The DPRK has sixth nuclear test ready.The DPRK may have a fusion cell like the Soviet RDS -37. “They can put in as much hydrogen as they need to raise kiloton yield . The January 2016 fourth nuclear test was released 7-10 KT with at least a large part from fusion . DPRK must prove it is a “full fledged nuclear power” before the new US president arrives . The fifth test was to improve efficiency of starting fusion reactions so as to conserve limited reserves of some fissile materials doubling or tripling their nuclear warhead arsenal .
      On the military front, the US plans to dispatch a nuclear-powered aircraft carrier to South Korea next month in a show of force to deter further military provocations…… slated for Oct. 10-15. Past US threats have been met with a show of force by DPRK . The DPRK and China see the US carrier as threat and insult . US DOD experts will consider all arguments that if attack is inevitable then sooner against smaller arsenal is better than latter against larger arsenal. This argument is eliminated if the US could peacefully coexist with nuclear DPRK . The desire to attack DPRK is fueled by goal of one world superpower with one world common law system with absolute power concentrated in hands of a few. Absolute power corrupts absolutely even corrupting good judgment. The governments of South Korea and Japan will not participate in a vote to begin nuclear war . A nuclear first strike is not approved by a democracy. Every DPRK nuke spent on Japan or South Korea is one that will not reach the USA. Placing US military systems in the Pacific ocean,South Korea, and Japan assures their value as targets consuming potential warheads. Despite this the DPRK claims enough warheads able to reach USA to turn it into “sea of fire”. They claim that capability now more than ever before.
      The USSR and Russia lived in fear of US nuclear strike for decades despite nuclear arsenal in the thousands and excellent delivery systems.To pursue their nuclear program ,the DPRK accepted a higher risk of nuclear first strike than USSR or Russia ever had.The underground defense shelters convince the leadership that their constitution can survive a repeat massive bombing assault again. The DPRK nuclear program passed the point of no return long ago .There is no trust of DPRK in US treaties.The DPRK only trust more nukes and better delivery systems .The DPRK understood the lessons of Saddam and Qaddafi . Nuclear war could kill many or even most of DPRK citizens as conventional bombing did before. But the DPRK constitution will survive just as it did before in Korean conflict bloody but unbowed. The argument of bombing the DPRK into submission was made in Korean conflict and proved wrong before. This time the DPRK can dispense the pain and not merely receive it. ..

    • Jonah Speaks (History)

      The hawkish view is not so easily dismissed. The bombing of Seoul or Tokyo is only a worst case scenario. If either happened, even DPRK knows that the U.S. would be coming against Kim with full force. It would be a suicidal move. Not even China would stand in the way.

      One could argue that the only thing worse than Seoul or Tokyo being put at risk is the whole U.S. (or Russia or China) being put at risk by further North Korean build ups. Both Presidential candidates are hawks, who might be willing to risk military action now for long term reduction in nuclear risk. Such military action might consist of conventional attacks on nuclear and missile facilities (not leadership), with clearly defined limits the U.S. chooses not to cross, unless the DPRK responds foolishly.

      If one takes regime change off the table (absent suicidal moves by DPRK), it is possible to negotiate limits on the DPRK missile and nuclear program, even as there may be some military attacks on parts of that program. The threat of such attacks may also be a motivator, particularly if there are also some carrots for coming to a deal. I am not saying this is the best strategy, only that a hawk might choose this course of action.

  4. Matthew R Brown (History)

    Joshua just curious, what would a KN-08 test campaign look like? Where would NK be able to test fly such a long range missile?

    • Joshua Pollack (History)

      I’d guess over water, as they have with other missiles and space launchers. If they want to avoid going over the main islands of Japan, they can either launch to the south, they way they now do with space launches, or they can do a lofted launch (almost straight up), as they have with their IRBM and SLBM this year over the Sea of Japan.

  5. Leandro (History)

    Mr Pollack, regarding countermeasures, I don’t quite understand something.

    What is the angle, minimal altitude and effective range for THAAD?

    I mean, can it intercept a NK ballistic missile at launch/acceleration phase when it’s going up, or is it designed for killing mid-flight missiles and/or reentry vehicles? What about low or mid altitude?

    This comes related as to what advantages (if any) has SK with the deployment of a (say two?) batteries in it’s territory. Every THAAD test I found about was related to intercepting long range incoming weapons, but that wouldn’t be a counter-deterrence for, say, saving Seoul. It seems designed to act against LRBM’s or ICBM’s, yet a couple of PAC-2 or PAC-3 near the border would look like a better alternative against Scud’s and the like.

    I mean, of course lending that ground for a system dedicated to avoid launches that aim for Japan or US forces in the theater (or the West Coast for that matter) is an obvious reciprocity for the US nuclear umbrella and conventional deployment. But all the fuss about THAAD leaves apart the fact that half of South Korea is effectively in range for low flying, shorter range missiles that would leave little to no reaction time.

    • Joshua Pollack (History)

      I’m not not technical enough to answer your THAAD questions, but can say that I don’t think it’s intended to protect the northernmost third or so of South Korea. But the other 2/3rds is where a lot of important things are, e.g., airbases.

  6. David Wright (History)

    Josh-I wanted to explain why I, and I assume others, model a 2-stage TD-2 rather than a 3-stage version. It’s true the Unha uses 3 stages, but the upper stage we have seen them fly has low thrust. In particular, it appears to use something like the steering engines from the SSN-6, and therefore that stage has a vacuum thrust of only about 3 tons. We estimate the stage itself has a mass of somewhat more than 3 tons, and the engines have to accelerate that mass and the payload. That worked for its satellite launches because most of the burn of this stage was on a relatively horizontal part of the launch trajectory, so it was speeding the satellite up to insert it into orbit without lifting the stage against gravity. Also, the satellite was likely less than 100 kg. If instead you are launching on ballistic missile flyout trajectory, the stage would be trying to lift the stage plus its payload of 500 kg or more against gravity.

    So using the Unha as a 3-stage ballistic missile would not have the range to cover the US if carrying a nuclear weapon. You can imagine different designs that NK might try to convert this to a 3-stage ballistic missile, which is what I assume the reports you cite have done, but it’s guess work since we haven’t seen such a stage. NK instead may be focusing on the KN-08 for its ICBM.

    • J_kies (History)

      David is correct that long burn low thrust systems make poor ICBMs due to gravity losses. As to the reasons why rational people don’t do ‘road mobile liquid hypergolic propellant ICBMs’ I simply point to design margins and the results of failures (see ‘the Nedalin catastrophe’). The DPRK isn’t particularly ‘nice’ but they certainly appear rational.

    • Joshua Pollack (History)

      Thanks, David, for that really interesting discussion!

    • George William Herbert (History)

      I was going to reply in more depth and then this happened:

      …so I will reply in brief.

      For an upper stage, even a missile not just orbital, once you’re moving an appreciable fraction of orbital velocity horizontally the gravity losses diminish. It helps if your upper stage has high thrust but is not absolutely required. (insert long complicated math arguments back and forth, which I have a wonderous proof for but no time to explain at the moment THANKS KIM…)

      And, really, a four-vernier two-cluster version of the current upper stage is not that hard a leap, and would bring initial stage T/W to about 2.0 anyways…

    • Joshua Pollack (History)

      David – I don’t know how, but until just now, I somehow missed your August post that dealt with these issues.

      It’s good to have independent expert analysis! The next question we might consider is why there seems to be such a stark disagreement between the two sets of assessments.

  7. J_kies (History)

    Lest anyone be in any doubt; open source reverse engineering looks at the KN-08 have included a lot of reasons why its expected to not be a credible ICBM (bad design, bad constraints). The more recent item claimed as a Hwaesong13 similarly has poor optimization as an ICBM. Those clearly have all the credibility of paper-mache’ threats.

    On the other hand; swapping out the tested Unha-3 stage 2 for something closely related to the Hwaesong-10 would provide a very credible 2 stage ICBM with a burn time near 220 seconds and would feasibly drop something near a metric ton on WDC (~10500 km+)

  8. badtux99 (History)

    One reason why reporters are reluctant to rely on “official sources” for the range of this missile is exactly the Iraq WMD debacle, where reporters got spun by “official sources” whose information turned out to be lies being spread for propaganda purposes. The issue then becomes one of, how can we tell whether we’re being used for propaganda purposes again? Then there are still some reporters who remember Iraq’s SCUD missiles in 1992 and how we were told they presented such a threat to Saudi Arabia and Israel. In the end they were so inaccurate that they were, at best, a terror weapon rather than a serious threat. There’s no indication that North Korea has improved their missile guidance systems significantly over the SCUD. In the end, what’s going to tip the scales for reporters is seeing the missile actually tested and getting the observations from multiple disinterested sources. Until then, as far as reporters know they’re just being used for propaganda purposes by “official sources” again.

  9. Cthippo (History)

    I think we’re spending entirely too much time thinking about the Unha. It is clearly a space launch vehicle and not a weapons system. Sure, you could theoretically strap a warhead on top of it and drop it somewhere in the general vicinity of a North American target, but you have to plan the shot months in advance and you can only do it once because there is only one gantry.

    While the technology does carry over to actual weapons systems, if we’re going to worry about the Unha as an ICBM then we should probably be more worried that two private companies in the US are building and launching ICBMs.

    • J_kies (History)

      Sir; the Unha exists and has demonstrated capabilities. If properly optimized at the second stage (say that Musudan swapped back in as stage 2) the Unha/TD-2 is extremely credible. Two flight tested rockets integrated together is a vastly easier and faster project than a new system. I would suggest that while a silo would be needed, nothing in particular forbids the DPRK from having tunneled around and built unannounced silos for TD-2s.

  10. George William Herbert (History)

    What the new engine can potentially do is much more worrysome.

    • J_kies (History)

      George; an 80 T, 200 sec burn engine is more suited to an SLV than their current stuff with the ND quad. If they quit messing around with hypergolics and went to LOX-Kerosene for better performance they would be building an SLV that the rest of the world would accept as an SLV.

  11. Chris Valade (History)

    Is there any evidence that the DPRK has deployed nuclear weapons? The recent test has brought statements about standardization etc. which seem to suggest deployment is ongoing or at least imminent.

    • George William Herbert (History)

      Suggest. I don’t know how we’d know if they had deployed it, from open source info.