Comment: Why We Shouldn't Snigger At North Korea

It would be easy to snigger at North Korea's somewhat unspectacular test of what purported to be a submarine-launched ballistic missile (SLBM) given that it almost certainly was no such thing.

However, even though it is tempting to imagine a couple of frogmen giving the missile a bit of a heave out of the water, the test does mark an advancement for the dictatorship's plans to be able to launch nuclear missiles from beneath the waves.

US military sources believe the missile was probably not fired from a submarine, but from an underwater platform. This is based on a number of factors not least that North Korea is not thought to have a submarine large or modern enough to fire a ballistic missile.

The missile North Korea's "Dear Leader" was photographed pointing at only flew for about 150 metres according to South Korean intelligence officials quoted by local media.

As an ballistic missile, capable of hitting the USA, or even Japan, this was not impressive, but worthy of note is that North Koreans got the missile out of the water, and that its engines then fired, taking it up. 

A rocket's engines must fire after it leaves a submarine or they risk destroying the vessel.  This allowed scientists to measure its speed and potential range and payload.

Therefore North Korea has probably just conducted a successful ejection test. This allows it to move on to the next stage of getting one to fire out of a sub.

Doing this is many times more complicated than a land-based launch and Pyongyang is probably several years away from being able to so do, nevertheless, it is on the way.

On paper their submarine fleet is impressive consisting as it does about 70 vessels.

However, most of these are mini subs for use in a potential war with South Korea, their largest versions are the Chinese Type 033 vessels which are due to be replaced by the similar sized Sinpo class, and neither Type could be used to launch a ballistic missile.

There are further problems; they lack the range to get within 1,500 miles of the American mainland, and back home, without refuelling. Nor can they spend long periods underwater without surfacing and therefore risk being spotted.

So the Pentagon, and it's South Korean and Japanese equivalents will not yet be having sleepless nights about the sea-based nuclear threat from North Korea, but they know this is a longer term problem they need to closely watch.

Mastering SLBM technology, and matching it with a vessel able to operate undetected, is a step change in any nation's nuclear defensive and offensive abilities.

Theoretically it reduces the chances of being hit by a first strike as it means a second strike retaliation capability probably survives due to being is sea based. It also hugely increases first strike capability, because SLBMs are far harder to detect being prepared for launch than the land-based versions.

The test must be seen in this light - as must a statement made this week in South Korea by the US Secretary of State John Kerry, that the Americans still hope to deploy state of the art missile defence systems in the South even though they are opposed by China.

He did not refer directly to the 'Terminal High-Altitude Area Defense', or THAAD batteries in which South Korea has expressed an interest, but if the North continues to advance its nuclear missile technology that interest will grow.

Arguably South Korea already needs THAAD due to North Korea's huge arsenal of missiles, some of which theoretically could be nuclear tipped.

Adding a sea based threat to this is something neither the Washington White House, nor Seoul's Blue House are inclined to snigger at.

Tim Marshall was formerly the Diplomatic Editor at Sky News. He can found at www.thewhatandthewhy.com and @Itwitius