It's easy for a totalitarian state to produce propaganda. There is no independent media, after all, to correct any lies. North Korea's nuclear weapons programme is shrouded in half-truths — mainly claims that its existence is necessary because neighbouring countries have similar ambitions. These allegations are probably false, but they would be easier to ignore if Japan and South Korea stopped fuelling North Korea's misinformation machine.

Earlier this month, for example, South Korea admitted that its scientists conducted experiments in 2000 on enriching uranium, and around two decades earlier on extracting plutonium from nuclear waste. By not reporting either project to the International Atomic Energy Agency (IAEA), the South violated the Treaty on the Non-Proliferation of Nuclear Weapons. The fact that this didn't come out until it was discovered by IAEA inspectors makes matters worse.

North Korea is stalling on attempts to resume talks over its weapons plans, and quickly used the revelation as proof that it needs a nuclear capability. The country is so adept at diplomatic smoke and mirrors that nuclear analysts are unsure of the size of its nuclear arsenal, or indeed if it has one at all. But it is clear that North Korea has an active nuclear programme, and the South Korean revelations have dimmed hopes that talks aimed at ending that work will resume in the coming months.

Sadly, this is not the first own-goal scored by North Korea's neighbours. In January 2003, Japan revealed that 200 kilograms of used plutonium was missing from its nuclear power complexes. Japan is also building a massive reprocessing plant for spent fuel, which could be used to produce plutonium. This, as North Korea has repeatedly pointed out, is a fuel for nuclear weapons as well as for nuclear reactors.

In truth, there is no evidence that either South Korea or Japan has a centralized weapons development programme. The hole in Japan's nuclear accounts was due to shoddy monitoring, not underhand weapons plans, the IAEA said following an inspection a month after the revelation. The agency gave the country another vote of confidence this month by halving the size of its inspection team there.

North Korea's more serious allegations about South Korea will probably also prove baseless when an IAEA team reports on the clandestine experiments next month. But the South cannot be completely innocent. Somewhere down the line, someone decided to push the research and scientists played along. Claims that the experiments were conducted in the name of basic research seem hard to believe given their obvious potential weapons applications. Many industrialized countries have the resources and expertise to conduct such experiments. Maintaining such a capability does not breach the non-proliferation treaty; doing the experiments clearly does.

On the Korean peninsula, such breaches give North Korea another reason to insist on its right to build nuclear weapons. Mismanaging nuclear resources, even civilian ones, has the same effect. That can seem a harsh lesson to have to learn when dealing with a country as manipulative and dishonest as North Korea. But if the region is to avoid a nuclear arms race, the scientists and rulers of countries that have sworn not to build nuclear weapons must stick firmly to the IAEA's rules.