North Korea has carried out five nuclear tests since 2006, so it unquestionably has the capacity to create some form of nuclear bomb.
To function effectively, however, the bomb needs to be small enough to fit on to a missile. Some experts believe the North has already “miniaturised” its nuclear capability, while others believe the regime is still several years away from being able to do so. Japan’s defence ministry warned on 8 August that it was possible that Pyongyang had mastered miniaturisation.
North Korea would also need a reliable delivery system for any bomb.Its proven short- and medium-range missiles could reach South Korea and Japan. In July it test-launched two intercontinental ballistic missiles, placing US cities in range of potential attack, according to US experts.
But at the end of a week that featured warnings from
Donald Trump to counter North Korean provocations with fire and fury and Pyongyangs detailed plans to create an enveloping fire around the US Pacific territory of Guam Japan has reason to be concerned.
All 14 of the missiles
North Korea has launched this year were aimed towards Japans coast, including two intercontinental ballistic missiles tested last month. Few here have forgotten that in 1998, a North Korean long-range missile overflew Japanese territory before splashing into the Pacific.
A missile fired directly at Japan would give people less than 10 minutes to seek shelter, according to experts.
Pyongyang said four Hwasong-12 intermediate-range ballistic missiles would pass over three Japanese prefectures, including Hiroshima, on their way to targets 30-40km off Guam.
In response, Japans defence minister, Itsunori Onodera, has warned that Japan is within its constitutional rights to shoot down the missiles since, by his reckoning, they represented a threat to Japans existence as a nation.
In an unusual move that will not have escaped Pyongyangs attention, Japans defence ministry on Saturday ordered the deployment of missile defense systems in four regions along the missiles probable flight path.
To emphasise the sense of readiness, local media carried photographs of PAC-3 interceptor batteries being positioned in the grounds of the defence ministry in central Tokyo.
controversial legislation enacted last year that gives Japan, under certain conditions, the right to exercise collective self-defence or come to the military aid of an ally under attack most likely the US.
Some experts, and Japanese opposition MPs, claim the unveiling of missile-defence hardware is purely symbolic, given the myriad technical challenges posed by intercepting a missile flying at high altitudes in the direction of a territory more than 1,500 miles away.
If the four planned missile launches pass over Shimane [a prefecture in western Japan] and Okinawa, its hard to see Japan having the capability with its existing facilities to intercept the missiles, said John Nilsson-Wright, senior research fellow for north-east Asia at Chatham House. I would be surprised if Japan is ready or equipped independently to do this.
The brinkmanship between North Korea and the US escalated after Japans defence ministry said in a white paper published last week that North Koreas nuclear weapons had
reached a new stage, adding that it was possible the regime had acquired the ability to miniaturise nuclear weapons. Hours later, US media reported that officials in Washington had reached the same conclusion.
Japans conservative prime minister, Shinzo Abe, the first foreign leader to
meet Trump after his November election victory, has refrained from joining countries such as Germany, China and Russia in criticising the USs intemperate remarks.
In one sense, heightened tensions between Pyongyang and Washington are strengthening Abes case for a more robust military, although his plans to revise the countrys pacifist constitution have been all but sunk by a
spate of scandals.
Jeff Kingston, director of Asian studies at Temple University in Tokyo, said: In the spirit of not wasting a crisis, Team Abe is making a case for beefing up Japans capabilities at a time when the public has been exposed to an unending escalation of rhetorical jousting between Trump and Kim.
Kingston believes the war of words reverberates ominously in Japan, which has just commemorated the atomic bombings of Hiroshima and Nagasaki 72 years ago.
While Americans ponder, with growing unease, the day when experts confirm North Koreas ability to send a nuclear warhead across the Pacific and back into the atmosphere in the direction of a US city, Japanese citizens, and locally based US forces, know that they are already theoretically within the regimes nuclear, chemical and biological weapons.
The announced flight path of the missiles targeting Guam, even naming specific prefectures (counties) in Japan over which they will pass has raised the national blood pressure, Kingston said.
During visits to Hiroshima and Nagasaki last week, Abe repeated Japans support for a global ban on nuclear weapons, even as it boycotted a
UN conference discussing exactly that.
But sabre-rattling by North Korea, combined with concern over Chinese military activity in the East and South China seas, has sparked a fledgling debate on a longstanding political taboo an independent Japanese nuclear deterrent.
Half a year ago, I would have said not a chance, said Nilsson-Wright. The nuclear allergy has simply been too strong to allow Japan to seriously consider opening the door to nuclear armament.
But, he added, weakened confidence in the USs ability, or desire, to defend Japan, coupled with growing support for a nuclear deterrent among South Korean voters, might, just possibly, persuade Japan to start thinking the unthinkable. But were still a long way off from such a scenario.
While no senior politician in Tokyo has seriously suggested acquiring a nuclear deterrent, the coming weeks will bolster those, including Onodera, who argue for a looser interpretation of the postwar constitutional constraints on Japans military, which limit it to a strictly defensive role.
Onoderas wish list is acquiring the ability to launch a preemptive strike at North Korean missiles on the ground if it believed an attack was imminent. That would mark an abandonment of a decades-old consensus that it can only destroy missiles targeting Japan itself.
As Tokyo and other big cities emptied out this weekend for the O-bon holidays, held to honour ancestors, many Japanese were casting a wary eye not just at Pyongyang, but also at the US and closer to home.
North Korea is seen as dangerous, said Koichi Nakano, a political science professor at Sophia University in Tokyo. But in trying to exploit fears over North Korea, Abe, like Trump, is also seen as adding to the danger.