John Everard is a former British ambassador to North Korea. The opinions in this article belong solely to the author.

Despite North Korea's strong denial, it now seems almost certain that North Korea was indeed behind the killing. VX is very difficult to obtain -- but North Korea is known to manufacture it , according to organization Nuclear Threat Initiative.

This was a horrible thing to do -- and also very stupid.

It was stupid because, just as it seemed that nothing could make North Korea's international position any worse, Pyongyang may have found an action that did exactly that.

The use of a chemical weapon will open up a whole new confrontation between North Korea and the international community, to add to the constant battles already over its nuclear and missile programs and its appalling human rights record.

Because the UN Security Council has banned North Korea from possessing -- let alone using -- chemical weapons, we can expect a flurry of activity in New York, and probably new, tougher sanctions on North Korea.

It was stupid too because it strains badly relations with North Korea's few remaining friends.

Malaysia had a genuinely warm relationship with North Korea. North Koreans can travel to Malaysia without a visa, and just days before the killing the two countries had signed an agreement on cultural cooperation.

Immediately after the killing, Malaysia said that it had no wish for this relationship to be hurt but North Korean antics, including vitriolic verbal attacks on Malaysia and an attempt to snatch Kim Jong Nam's body from the morgue , have frayed Kuala Lumpur's patience.

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The discovery that the North Koreans may have released a lethal toxin in its main international airport would test even the most solid international relationships. Malaysia's deputy prime minister has ordered a review of relations with North Korea and the foreign minister has talked of expelling North Korea's ambassador (Malaysia has already withdrawn its man in Pyongyang).

The airport authorities had to close the busy terminal for decontamination, and they doubtless thank their lucky stars that residual VX has not hurt any passengers since the killing.

But perhaps worst of all for North Korea, the events will have infuriated China -- North Korea's only true ally and principal supporter. Following Kim's death, China announced that it will implement strictly the UN Security Council requirement to stop any further coal imports from North Korea this year, thus halting over a quarter of North Korea's total exports.

China has not yet reacted substantively to the news that VX was used, which almost certainly means that senior leaders are considering what to do. Kim Jong Nam was under Chinese protection, and China hates anything -- like using VX in an airport -- that threatens stability. Beijing's leaders will not be pleased.

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Finally, it was stupid because the assassination was botched so badly.

Properly executed, the removal of a high-value target using a sophisticated nerve agent might impress some people -- it would probably have the terrorists of ISIS drooling with envy. But, probably because they were afraid to handle the VX themselves, the hit team, incredibly, entrusted the actual killing to two inexperienced civilians, Malaysian police have said.

Both were promptly arrested and are talking to the Malaysian police.

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Then the North Koreans failed to recover Kim Jong Nam's body, which enabled the Malaysians to conduct tests that showed a horrified world that North Korea had used VX.

The day after the attack, Kim Jong Un appeared on North Korean television chairing a big political meeting. Usually smiley on such occasions, he scowled and did not even wave to his comrades. He is not a happy dictator -- and for good reason. North Korea's stock has sunk to a new low.