Just a few days after one international gunrunner was arrested, another has been set free. Russian Viktor Bout, known as the ‘Merchant of Death’, was detained in Thailand on 6 March for conspiring to supply arms to Colombian FARC rebels. Four days later a court in the Netherlands overturned the 2006 conviction of Guus van Kouwenhoven, a Dutch citizen who had been sentenced to 8 years in prison for violating the UN arms embargo on Liberia.

Bout was arrested by Thai police acting on a warrant issued by the US Drug Enforcement Administration. The US is seeking his extradition. His accomplice, British-born South African Andrew Smulian, was arrested in the US on the same charge of conspiring to provide arms to the FARC.

Bout has also supplied weapons to embargoed destinations such as Angola, DR Congo, Liberia and Sierra Leone, according to UN and NGO reports. However, he has never been prosecuted for gun trafficking because of the inadequate laws in most countries regulating arms brokering and arms transporting activities. Bout, who operates under several different names and passports, was the inspiration for the lead character played by Nicholas Cage in the film Lord of War.

Even in countries with good laws, it is difficult to convict arms brokers because direct evidence is often unavailable. Guus van Kouwenhoven was the owner of OTC, the most notorious logging company in Liberia according to Global Witness. He was arrested after being placed on bans for both travel and assets by the UN Sanctions Committee on Liberia. He was convicted for violating the UN arms embargo in exchange for timber. But the evidence relied on statements from unreliable witnesses, according to the Netherlands Court of Appeal.

Click here to read the views of Claire da Silva, an international lawyer who works with the Control Arms campaign for an Arms Trade Treaty.