South Korea has been digging into North Korean weapons smuggling efforts, and has found an elaborate, and widespread network of organizations and people that make it all work. What gave South Korea an opportunity to penetrate this web of deception was the recent seizure of an Il-76 transport carrying 40 tons of North Korean weapons.
The weapons laden Il-76 jet transport seized in Thailand last December turned out to be the third such aircraft to pass over Thailand recently. U.S. intelligence has been tracking cargo transports flying out of North Korea, and an increasing number of these flights take the southern route (rather than via China and Central Asia.) A more thorough inspection of the cargo on the seized Il-76 found components for North Korea's Taepodong-2 ballistic missile. This weapon has three times the 2,000 kilometer range of Iran's current largest missile. If Iran is building their version of the Taepodong-2, they will be able to hit targets throughout Europe. The Il-76 apparently planned to make stops in Sri Lanka, the United Arab Emirates and Ukraine, before delivering the missile parts to Iran.
The South Koreans uncovered a smuggling network that had components in Ukraine, Central Asia, New Zealand, Hong Kong and the Persian Gulf. What built all this was North Korea's need to export its weapons, despite international embargos, to earn hard currency. The North Koreans needed the money to keep their communist police state going. For the North Koreans, the smuggling is a matter of survival, and that is a great motivator.