The United Nations High Commissioner for Refugees (UNHCR) has helped over 3.69 million Afghan refugees return to Afghanistan since March of 2002, marking the largest assisted return operation in UNHCR's history. In addition, more than a million refugees have returned to Afghanistan without availing themselves of UNHCR's assistance (also known as "spontaneous returns") bringing the total number of returnees to 4.8 million or more. Almost all of these Afghans have returned from neighboring Iran and Pakistan, where the vast majority of Afghan refugees have lived for well over two decades (see Table 1 ). Issues of particular concern to the 110 th Congress are 1) continuing and sustaining refugee returns as part of Afghanistan's overall reconstruction; 2) developing funding strategies for the next phase of Afghanistan's remaining refugees; and 3) examining the refugee situation in light of border security issues, particularly with regard to Pakistan's recently announced plan to lay land mines and build a fence along its border with Afghanistan. In the long term, the impact of Afghan migration trends may need to be better understood in light of its potential impact on political arrangements in South Asia. Afghans began fleeing their country in April 1978, when the Marxist People's Democratic Party of Afghanistan (PDPA), overthrew the government of Muhammad Daoud (who had himself seized power from his cousin Afghan king Zahir Shah in a bloodless coup in 1973). The trickle of refugees accelerated when the Soviet Union invaded in December 1979, ostensibly to restore order to the country as the PDPA became increasingly splintered. While political infighting was certainly a problem, some observers also noted that Afghanistan's leadership had begun irking Moscow by making decisions without Soviet approval. The Soviet attempt to subjugate the Afghans was at times particularly brutal, including the alleged use of torture and collective punishment. By the beginning of 1981, some 3.7 million refugees had fled to Iran and Pakistan. Smaller numbers of refugees continued to flee Afghanistan for the next decade, as the Soviets fought an insurgency mounted by a loosely allied group of mujahideen , or holy warriors. In 1988, the Soviet Union agreed to withdraw from Afghanistan, and UNHCR and the international assistance community prepared for the massive repatriation of refugees. Large-scale returns did not begin until 1992, however, when the Soviet-installed leader Najibullah was finally forced from power. No sooner had some million and a half refugees returned, however, than Kabul descended into armed disorder as various mujahideen factions began fighting for control of the capital and the surrounding area. A new wave of people was displaced (possibly up to a million), a majority of whom remained within Afghanistan's borders as internally displaced people (IDPs). After a year-long siege, the Taliban took Kabul in 1996, and had gained control of most of the country by 1998. Although they brought a measure of peace to the areas they captured, many Afghans, especially the educated, fled the Taliban's particularly austere vision of Islamic propriety, with its severe restrictions on women's activities, education, and social and cultural life. A final wave of refugees numbering 200,000 to 300,000 left Afghanistan during the U.S.-led invasion of October 2001. With the defeat of the Taliban a month later, UNHCR led consultations with the three governments centrally involved in the Afghan refugee issues—Pakistan , Iran, and Afghanistan—and began planning for another mass repatriation. Beginning in 2002, UNHCR along with Afghanistan, established separate Tripartite Agreements with Pakistan and Iran to provide a legal and operational framework for voluntary repatriations from each country. These agreements have been renewed several times since then. The working assumption at the time was that there were approximately 2 million refugees in Pakistan and 1.5 million in Iran. Almost everyone was caught off-guard, when subsequently 2.15 million Afghans returned in 2002, and yet most of the camps in Pakistan (and to some extent the cities in Iran) continued to house large numbers of Afghan refugees. It turned out that there were far more Afghans living in Pakistan than most analysts had thought. Although the numbers of returns declined in subsequent years, it can be seen from Table 1 that through 2005 the pace remained very strong. UNHCR estimates that, as of December 2006, perhaps 2.46 million registered and unregistered Afghans are currently living in Pakistan and more than 900,000 in Iran. Who among these Afghans is a refugee and who is not is a matter of debate in each country. Still, perhaps as many as 3.5 million registered and unregistered Afghans still live in exile. In Pakistan, 80 percent of those remaining have been there for more than two decades; 50 percent were born in exile. A census was completed by UNHCR and the Government of Pakistan (GoP) in March of 2002 that provided a clear picture, for the first time in years, of the Afghan population in Pakistan. The census found 3,049,268 Afghans living in Pakistan, 42% of them in camps and 58% in urban areas. Over 81% of the Afghans were Pashtuns, with much smaller percentages of Tajiks, Uzbeks, Turkmen, and other ethnic groups (see Figure 1 ). The census revealed two related factors that could have profound implications for the future of repatriation from Pakistan. First, the vast majority of Afghan families in Pakistan arrived in the first years of the refugee crisis; over 50% arrived in 1979 and 1980 alone. Second, it appears that a very substantial number of the Afghans remaining in Pakistan were in fact born in Pakistan—not Afghanistan (see Figure 2 ). Encouraging Afghans who have been living for two and a half decades outside their country—some of whom, in fact, may never have even set foot in Afghanistan—to repatriate may be a distinct challenge in the coming months and years. Although most Afghans in Pakistan date their arrival to the early years of the Soviet occupation, agricultural and economic instability have long been a feature of life in the highlands of Afghanistan, and for centuries Afghans have migrated in response to crop failures, drought, and other problems, often across international borders, to look for temporary work. While the numbers crossing into Pakistan in 1979 and 1980 probably dwarfed any previous population flows, many of the fleeing Afghans had connections—social networks, kinship ties, economic contacts—in Pakistan that helped ease their transition. For the first decade and a half of the refugee crisis, the GoP, although it has never signed the 1951 Refugee Convention or the 1967 Protocol, was relatively tolerant in its treatment of Afghan refugees. Several dozen camps were set up beginning in 1979, most of them in the Northwest Frontier Province (NWFP) and a few in Balochistan. Although the GoP did not allow the primarily rural Afghans to own or work the land, it did permit them to freely move and work within the country. Nevertheless, it was assumed at the time that most Afghans remained in the camps, where they received food rations, along with basic health and educational services. (The subsequent realization that there were far more Afghans in Pakistan than anyone knew suggests that urbanization was far more extensive during this period.) The camps were, and are, overseen by UNHCR and the Pakistani Chief Commissionerate for Afghan Refugees (CCAR), a division of the Ministry of States and Frontier Regions (SAFRON). UNHCR and CCAR contracted with a number of international and local NGOs to provide health, education, water, and sanitation services in the camps. These have included major U.S.-based NGOs, including Mercy Corps, International Rescue Committee, Save the Children, American Refugee Committee, Church World Service, and others. In 1995, the World Food Programme (WFP) determined that Afghans were capable of providing for their own food needs, and it ceased providing rations to the camps. The GoP's position toward the refugees began to harden as the flow of international aid began to diminish, and more Afghans were driven into cities to look for work. With the cessation of food aid, the sole identity document given to Afghans, a refugee passbook, became meaningless; therefore, Afghans (until very recently) had no identification in Pakistan, a factor that doubtless contributed to the general uncertainty about their numbers. With the defeat of the Taliban, the GoP began strongly advocating that conditions were appropriate for the return of all Afghans to Afghanistan. The GoP appears to have both economic and security concerns about the Afghan population in Pakistan. On the economic level, some Pakistani politicians believe that Afghans are taking jobs that might otherwise go to Pakistanis. Additionally, Afghans are reportedly willing to work for lower wages than Pakistanis, causing some Pakistanis to believe that wage levels are being depressed. Some recent research has shown that several business sectors—particularly transport and construction—make heavy use of Afghan labor. Economic worries about the Afghan population have become more persistent in recent years, as the overall level of international funding for refugees in Pakistan has decreased. The census provided more fuel for this concern when it revealed that, despite the record repatriation, millions of Afghans still remain in Pakistan. In addition to their economic impact, some Pakistani leaders are concerned that Afghans represent a security risk for Pakistan. These fears concern lawlessness, terrorism, and anti-government activity. There is a perception among many Pakistanis, including government officials, that Afghans are responsible for a great deal of the smuggling of stolen goods, narcotics, and weaponry across Pakistan's western border.