It is estimated that there are more than 12 million stateless persons in the world. People without nationality "trapped in a legal limbo", according to the United Nations High Commissioner for Refugees (UNHCR) , because no state recognizes them as citizens. Together with refugees and displaced persons, they are one of the most vulnerable groups, which implies, in some cases, minimal access to legal protection or basic rights such as health. Some define them as "ghosts", invisible people to whom no country recognizes their citizenship. Along with refugees and displaced persons, stateless persons are one of the most vulnerable groups, representing millions of people around the world. "If nationality is the right to have rights, people to whom no country grants their nationality are in legal limbo."

Stateless people find themselves in this situation for a number of reasons. There may be a transfer of territory or sovereignty that alters the nationality situation, a conflict between laws is possible when the descendants are born in a country other than that of the parents, or it may happen that the State arbitrarily withdraws citizenship status. Other cases that lead to statelessness are: administrative or procedural problems to confirm or obtain nationality, the application of discriminatory practices based on ethnicity, religion, sex or political opinions, and individual renunciation of nationality without previously acquiring another.

The book incorporates interviews with experts in immigration matters between 2005 and 2013.