As things go in the arms trade, there are not many countries in the world that misbehave more than Iran. The country is under a UN-imposed arms embargo — it cannot buy and it should not sell weapons.

Iran, of course, has done its best to defy these restrictions, both by procuring sensitive military technology through intermediaries and front companies, and by exporting weapons to insurgents and proxies using the cover of innocent export items. According to a May 2011 report by the UN’s Panel of Experts on Iranian sanctions, since 2009, large Iranian cargos of weapons concealed inside containers had been seized. The weapons were destined for insurgents in the Niger Delta and for Hamas and Hizbollah. Rockets were hidden behind merchandise such as cotton, to fool unsuspecting port authorities. According to the same panel of experts, in their report on UN sanctions against North Korea, which was released in May 2010, the hermit kingdom also made numerous shipments of missile technology to Iran.

Nothing either shocking or surprising in all of the above — criminals, after all, will be criminals. Iran is being punished by the international community — and its criminal rulers seek to circumvent restrictions any way they can.

What is shocking is that this week, yet again, the UN system in charge of implementing its own decisions on arms trade and arms control has allowed Iran to be elected as a member of the Bureau of the UN Arms Trade Treaty Conference, alongside other 14 countries.

The Geneva-based human rights organisation, UN Watch, exposed this troubling development on Monday, noting that having Iran elected to this position is like “choosing Bernie Madoff to police fraud on the stock market”, as UN Watch executive director Hillel Neuer commented.

The UN process is often something that even Franz Kafka would gaze at in disbelief. Regardless, putting the thieves in charge of the bank vaults may be one step too far. Her Majesty’s government should invest more energy in the diplomatic struggle to prevent Iran and other rogues from getting the top UN posts. To let it happen is not just a mockery of the international order the UN purports to represent, but also a way to ensure that enforcing a safe arms control regime will become impossible to achieve.

Emanuele Ottolenghi is a Senior Fellow at the Foundation for Defence of Democracies in Washington