This chapter examines several challenges to human security. It reviews several issues associated with human security, including poverty, transnational crime, the global arms trade, refugees and migrants, human trafficking, and disease. Among poverty-related issues are economic development, foreign investment, and foreign aid, access to global markets, and global debt. All the major international economic agencies are involved in efforts to alleviate global poverty. Health and disease are linked to poverty. High birth rates in poor countries among people living in crowded conditions with inadequate sanitary and medical facilities provide fertile soil for spreading diseases such as HIV/AIDS, Zika, malaria, and cholera, a disease arising from contaminated food and water. High crime rates have a variety of causes including weak governments, poorly paid and easily corruptible government officials, poverty and unemployment, demand in wealthy states for illicit drugs, and poorly paid illegal migrants. Drug traffickers and tax evaders seek to hide their profits by money laundering.