This article is a case study of Burmese Karen refugees residing in refugee camps in Thailand. It examines how the relations between a host government and international relief agencies are shaped by the issues of security and economy and how these issues consequently affect the livelihoods of refugees. The study divides the history of Karen refugees into three periods: 1984 to 1995, 1995 to 2005, and 2005 to 2011. The influences on the government's attitude toward refugees and toward the international relief agencies are identified for each period and the modes of the refugees' livelihood are examined. The study contends that the host government's concerns about security and economy are key factors shaping the government's refugee policies, relations between the government and international relief agencies, and the mode of refugees' pursuit of a livelihood. When security issues are dominant, the attitude of the government toward international relief agencies is negative and consequently the refugees' options are restricted. In contrast, when economic issues are dominant, the government takes a positive stance toward international relief agencies, which play a bigger role, and the welfare of refugees improves.