Japanese and German sources report five facts are known for sure:

1. North Korea carried out two covert underground nuclear explosions in mid-April and around May 11 of 2010 equivalent to 50- 200 tonnes of TNT.

2. Two highly lethal heavy hydrogen isotopes, deuterium and tritium, typical of a nuclear fission explosion and producing long-term contamination of the atmosphere, were detected and analyzed by  Comprehensive Nuclear-Test-Ban Treaty Organization (CTBOTO) monitoring stations in South Korea, Japan and Russia.

3. The presence of tritium in one of the tests led several intelligence agencies watching North Korea’s nuclear program and its longstanding links with Iran and Syria to examine the possibility that Pyongyang had tested the internal mechanism of a nuclear warhead on Iran’s behalf.  This strongly indicated to German and Japanese intelligence that Iran had already developed the nuclear warhead’s outer shell and attained its weaponization.

4.  Another possibility examined was that North Korea had tested an Iranian “dirty bomb” – i.e. a conventionally detonated device containing nuclear substances. Tritium would boost its range, force and lethality.

This was one of the conclusions of atmospheric scientist Larsk-Erik De Geer of the Swedish Defense Research Agency in Stockholm, who spent a year studying the data collected by various CTBOTO stations tracking the North Korean explosions.

On February 3, De Greer published some of his findings and conclusions in Nature Magazine. His paper will appear in the April/May issue of the Science and Global Security Journal.

5. The Japanese and German sources found confirmation of their suspicions that North Korea had abetted Iran’s nuclear aspirations in three events:

a)   Shortly after the April explosion, a large group of Iranian nuclear scientists and technicians arrived in Pyongyang. They apparently came to take part in setting up the second test in May.
b)  In late April, Tehran shipped to Pyongyang a large quantity of uranium enriched to 20+ percent – apparently for use in the May test.
c)  Straight after the May test, the Central Bank of Iran transferred $55 million to the account of the North Korean Atomic Energy Commission. The size of the sum suggests that it covered the fee to North Korea not just of one but the two tests – the first a pilot and the second, a full-stage test.

It is not by chance that this incriminating disclosure about Iran’s nuclear achievements sees the light Monday, just hours before US Barack Obama receives Israeli Prime Minister Binyamin Netanyahu in the White house for an argument over an expeditious military action to stop Iran going all the way to a nuclear weapon (Debkafile).