UN sanctions have created some difficulties for Iran’s ability to export arms and procure illicit materials, but the regime’s use of front companies and other deceptive trade practices allow it to work around restrictions, according to a new UN report cited by the Wall Street Journal. The report notes that some countries are keeping a watchful eye on ports used by Iranian companies. Despite the increased awareness on the part of some countries, however, businesses set up by the Islamic Revolutionary Guard Corps (IRGC) continue to procure military items and export conventional weapons. Syria, Iran’s conduit for weapons shipments to the terrorist organization Hezbollah, received the majority of illegal arms shipments reported to the UN. “It is likely that other transfers took place undetected and that other illicit shipments were identified but not reported,” the report concludes.

This latest assessment demonstrates the limitations of sanctions as a policy tool. Getting them on the books is one thing, but the real challenge, one that has yet to be overcome, lies on the enforcement side. In the wake of the Arab Spring, Iran’s leadership continues to arm proxies, to import materiel for its weapons programs, and to reaffirm its unyielding stance on the nuclear issue.