The initial impetus for the United States to develop an international prisoner transfer program was concern over the poor conditions to which Americans convicted in some countries were exposed. The transfer program was viewed as a means of returning these Americans to the United States and allowing them to serve their sentences in American prisons. Concern over the prison conditions experienced by Americans incarcerated abroad, however, was not the only reason that the United States decided to institute the transfer program. Indeed there was a fundamental belief that the rehabilitative prospects of a prisoner were strongest if the prisoner was located near his home where he could be close to family and friends, in a familiar culture, and in a place where his native language was spoken. In addition, there was a recognition that transfer would provide a means to ease the diplomatic and law enforcement tensions that arise between nations when one country incarcerates another country's nationals. Transfer was also viewed as a means to ease the administrative burden experienced by the sentencing country when it incarcerated prisoners speaking different languages, having varying dietary needs, practicing different religions and having differing cultural and belief systems.
As the United States began to participate in the prisoner transfer process, it recognized that there were two other significant benefits to the program. The first was a law enforcement benefit while the second was an economic one. With respect to the law enforcement benefit, in many instances, prisoner transfer is preferable to traditional removal by immigration authorities. Traditional removal or deportation does not provide the receiving country with any tools, information, or authority to manage the deported criminal because it occurs after the sentence has been served. In contrast, prisoner transfer places the prisoner directly in the custody of foreign law enforcement officials who have been provided with detailed information about the prisoner, including official accounts of the criminal conduct committed. It also results in the prisoner having a criminal record in his home country. This transfer procedure permits the receiving country to acquire initial control over the prisoner, to monitor the prisoner's activities, to address any treatment or rehabilitative needs of the prisoner, to assist in the eventual reintegration of the prisoner into society and, when legally permitted to monitor the prisoner upon release.
Transfer also provides an economic benefit by saving the federal and state prison systems the cost of continuing to incarcerate the transferred prisoner. In the early years of the transfer program, the number of returning Americans exceeded the number of foreign nationals transferring from the United States. Over time the composition of the transfers has changed and now approximately 90 percent of the annual transfers are foreign nationals returning to their home countries.