Japan: A Future Nuclear Weapons Superpower?

Kyle Mizokami

Security, Asia

A geopolitical earthquake.

Key point: Tokyo could get the bomb if it needed to and that would be scary for its neighbors.

It is perhaps China’s greatest nightmare: a nuclear-armed Japan. Permanently anchored off the Asian mainland, bristling with nuclear weapons, a nuclear Japan would make China’s security situation much more complex than it is now, and force China to revise both its nuclear doctrine and increase its nuclear arsenal.

To be perfectly clear, Japan has no intention of building nuclear weapons. In fact, it has a strong aversion to nukes, having been the only country to actually be on the receiving end of a nuclear strike on its cities. Japan’s strategic situation would have to grow very dire for it to undertake such a drastic and expensive option.

At the same time, China has no interest in provoking Japan into building them. China’s nuclear “no first use” policy is in part aimed at reassuring Japan that, unless it were attacked first with nuclear weapons, it will not use them in wartime. Japan has no nukes, therefore, if China holds to its word, Japan should be reassured. “If” and “should” being the operative words here.

Still, it’s an interesting proposition. Nuclear phobias and the lack of a pressing need aside, there’s certainly no reason why Japan,the third largest economy in the world, couldn’t build nukes.

What would a Japanese nuclear deterrent look like? Let’s examine the traditional nuclear triad of land-based ballistic missiles, strategic bombers and ballistic missile submarines and each leg of the triad’s suitability for Japan’s circumstance. For the sake of argument, let’s say Japan can choose just one leg to invest in.

We’ll also set the number of nukes at roughly 300. Japan’s high population density would mean that the destruction of just a handful of cities could kill or injure the majority of the country’s civilian population. Against an adversary such as Russia or China, Japan must be able to inflict similar losses.

Land-based missiles: