This chapter focuses on the category of recent customers that are most difficult to convince to discontinue their custom: those whose ties to North Korea have weathered decades, including the nearly ten years in which sanctions have been in place. It outlines each of the main resilient customers during the period since 2006 and analyses their common traits. Senior officials in many of the countries analyzed in the chapter from Cuba to Uganda to Syria have reminisced publicly and fondly about Pyongyang's past contributions to their countries' national defence. North Korea also offered training to the Iranian military, in part to help it overcome problems of interoperability experienced as a result of having sourced weapons from around the world. Cuba, Syria, Iran and Burma have few possible sources of weapons-related goods and services, and armed groups in the Middle East may feel they need all the military support they can muster.