ANALYSIS - Japan buffeted by North Korea nuclear arms tests

- The author is a long-term resident of Japan and a renowned specialist in Japanese politics, affairs and intelligence

By Todd Crowell

TOKYO (AA) - Japan is on high alert following North Korea’s fifth underground atom bomb explosion which came on the heels of three ballistic missile tests whose dummy warheads fell close to Japan’s coast.

Defense analysts say it can no longer be denied that the North is seeking to become a fully-fledged nuclear weapons power with deliverable missiles capable of hitting any target in Japan, not to mention South Korea and American bases as far away as Guam.

The recent test -- Sept. 9 -- was the largest so far at 15-20 kilotons, which puts it on a par with the atomic bomb that devastated Hiroshima.

In the wake of a test last January, analysts quickly dismissed Pyongyang’s claim that it had exploded a thermonuclear, hydrogen bomb.

This time, however, they were not so quick to dismiss the North’s claim that it had operational nuclear weapons.

Defense Minister Tonomi Inada told reporters that it is now “appropriate” to assume that Pyongyang has solved the problem of miniaturizing nuclear bombs so that they can be attached to the warhead of a ballistic missile.

“We cannot rule out the possibility that with this nuclear test North Korea’s nuclear technology has reached a stage where it can aim for operation use,” a senior Japanese defense official told the Japan Times.

In the wake of the test, Prime Minister Shinzo Abe instructed the government to prepare a list of additional bilateral sanctions, while seeking more sanctions from the United Nations.

It is difficult to see what more Tokyo can sanction as almost any intercourse is already proscribed.

It is not just the nuclear test that is feeding growing anxieties. There have been more and more tests of delivery means, coming seemingly one after another.

In June the north successfully launched a Musadan medium range missile for the first time.

In August, a medium range Rodong type missiles landed in the Sea of Japan inside that country’s 200 nautical mile Exclusive Economic Zone (EEZ).

It was not strictly illegal, but Japanese might think it is a little too close for comfort. Moreover, it was a dummy warhead and not just missile casing.

Another potential dimension took place this summer when the North successfully launched a ballistic missile (SLBM) from a submarine.

The Japanese see the SLBM and Rodong missile as particular threats to security.

For that matter, the nuclear tests are coming with greater frequency.

There have been two this year, and there is speculation that Pyongyang might be another before the year is out as there have been three tests during Kim Jong-un’s relatively short tenure.

North Korea’s stocks of plutonium and highly enriched uranium (HEU) seem large enough now that they can be partially used up in underground tests.

Informed sources say that the North will have enough Pu/HEU to build 20 bombs by the end of the year and seven bombs per year after wards.

The United States has subsequently sent two nuclear capable B-1 bombers flying over South Korea as a show of force. In January the U.S. had sent a B-52 over South Korea. Both bombers are based in Guam.

The latest test hit South Korea at a time when relations with the North have been particularly strained.

The last element in the South’s attempts to seduce its neighbor into better behavior, the closing down of Kaesong Industrial Park -- one of few remaining symbols of co-operation between the two nations -- took place following the earlier test.

This week, South Korea's Yonhap News Agency published a leaked ministry of defense story about a doomsday plan known as the Korea Massive Punishment and Retaliation plan to “decapitate” the North's leadership if they feel a nuclear attack is eminent.

The memo asserted that the South had the capability of bombarding Pyongyang with medium range missiles, including those specifically targeted at Pyongyang’s neighborhoods where many of the leaders live.

“Every Pyongyang district, particularly where the north Korean leadership is possibly hidden, will be completely destroyed by ballistic missiles... as soon as the North shows any signs of using nuclear weapons,” the agency quoted from its source.

North Korea, however, has thousands of long-range artillery pieces positioned just across the border from Seoul, sufficient to turn the South Korea capital into a “sea of fire” as the North often says, even without the nukes.

China condemned the latest nuclear test but not very strongly.

It was another sign that trying to leverage Beijing into somehow dismantling or slowing down Pyongyang’s march to becoming fully fledged nuclear weapons state is futile.