The rapid development of North Korean ICBM capability exposed an apparent inconsistency with similar developments in other nuclear weapons powers.
Land based ICBMs, by their nature, are physically large missiles.Liquid fueled, they are difficult to transport whether empty or fueled. Solid fueled ICBMs are less problematic, but still require extensive maintenance if actively and routinely transported by road.
These problems have tended to restrict most ICBMs to either stationary land bases, or at sea where transportation by SSBNs is less stressful.
Mobile land based ICBMs, moved about on wheeled or tracked road transporter erector launchers or rail, expose missiles to many risks plus wear and tear.
To date, North Korea have demonstrated a variety of road mobile ICBM platforms that are mostly stored in bunkers. While it is well known that DPRK have extensive underground facilities, particularly for artillery, munitions, short or medium range missiles, none is known via open source intelligence to be dedicated ICBM missile silos like the US Minuteman silos. The PRC historically made extensive use of large underground bunkers with underground missile launch pads that are reloadable.
It is not known if North Korea is following this model.
But how are they going to base them in the near future when their ICBM arsenal reaches initial operational capability?
The most plausible explanation is that DPRK is moving toward solely relying on mobile TELs for their liquid fueled ICBMs. Liquid fueled ICBMs that are fueled on the launch pad require a large convoy of supporting trucks and many hours of preparation for launch.
This long lag time in the “open” enabled advanced detection of launch and at least in theory the possibility of pre-emptive strikes as a missile is fueled.
North Korea can, alternatively, master the delicate task of pre-fueling the missile horizontally prior to transport out of the storage bunker. That would shorten the time for launch to perhaps 30 minutes to an hour.
But that is still a significant window of vulnerability compared to the time required to launch a pre-fueled silo based missile, which can be launched in minutes or as quickly as the hatch can be opened.
If the choice is for a US style ICBM silo, it will likely to be large not only to accommodate the liquid fueled rocket, but potentially, large enough for “strap on” solid fueled boosters that may be required to lift an early generation thermonuclear warhead and missile packed with penetration aids and decoys from DPRK to anywhere in USA.
Construction of large ICBM silos can in theory be detected through several “national technical” means. While it cannot be ruled out that DPRK ICBM silo construction have escaped public notice, it is an open question whether they built them at all.
The PRC, who until the 21st century, had an “assured means of retaliation” posture that presumed their ICBMs in hardened silos will survive a first strike, and can be launched afterwards.
Though this may have changed to an offensive first strike posture at least for S/MRBMs aimed at near-abroad targets.
If the North Koreans have not invested in building hardened silos for their liquid fueled ICBMs, it can be a sign that they are expecting to field a mobile solid fueled ICBM shortly — and thus, sidestep the complexity of liquid fueled missiles.
Another explanation is that DPRK do not need or anticipate the requirement for survivability provided by basing liquid based ICBMs in hardened bunkers.
Or they feel that hardened silos (of the latest design) are not survivable anyways.
Not providing for survivability of an nuclear ICBM force is inconsistent with its use as a deterrent force.
Basing missiles in the “open” was an expedient measure used by the Soviets in the 1960s which was abandoned as soon as they found something better. It is preferable to enhance readiness and survivability by storing missiles in bunkers, silos, or place them on submarines.
Deterrent forces, by their nature, are systems that sit unused for extended periods: decades until they are obsolete without ever being used.
Occasional samples are tested to ensure the stock is reliable if ever needed. Thus, ICBMs on the US, Russian, Chinese, and Israeli models tend to be built to be long lasting, rugged, maintainable, and can be held at readiness for long periods with modest maintenance.
No expense is spared in making nuclear deterrent systems reliable and safe during their long periods of storage while ready to launch.
But are NORK ICBMs built this way?
Another line of reasoning is that DPRK intend to strike the first blow with their ICBMs — particularly using the liquid fueled versions that are most vulnerable once conflict broke out. If this is the case, the ICBMs will have to be able to penetrate known defensive systems like the US ground based missile defense (GMD) systems.
That suggests that NORK may not be concerned by giving advance warning of the launches as the US and allies have not historically been willing to cross the line to pre-emptively destroy a “missile test” launch.
But what if the “test” involved volley firing of (e.g.) 10 ICBMs?
The US have not responded proactively to the PRC and DPRK volley launching multiple missiles in “tests”. Thus, precedent favors no response if DPRK volley fired ICBMs in a “test”.
What if it is not a test?
The US will find out only when they see the trajectory heading across the Pacific.
Simultaneous firing of many ICBMs, mixed with IRBMs, will allow some of them to be used for blinding of sensors and destruction of key missile defense installations. (e.g. Japanese and other Pacific radar sites). Before PACOM can determine if the launch is “hostile”, their sensors and communications will likely be blinded and / or disabled.
Decoys, dummy missiles and warheads can overwhelm the small number of ABM interceptors leading to a high probability that at least one thermonuclear warhead will detonate over CONUS.
US posture biased against “provocations”, rather than contribute to stability and preventing nuclear war, encourage DPRK to adopt a surprise massive first strike strategy aimed at a Pearl Harbor like knockout blow.
Do the ICBM basing plans of DPRK reveal an offensive nuclear first strike strategy being put into place?
If so, it leads to very different calculations as to DPRK intent and longer term goals.
DPRK may not be deterred.