A person having two or more nationalities may be regarded as its national by each of the states whose nationality he possesses. This may result in excessive burdens being placed on the individual by virtue of multiple national obligations such as those relating to taxes or military service. With regard to diplomatic protection, a state may not afford this protection to one of its nationals against a state whose nationality such person also possesses. The individual's ability to select one nationality may be subject to limitations or restrictions in terms of his or her ability to renounce the nationality of one state or to retain the nationality of a state in circumstances which give rise to the involuntary loss of nationality under state law.
The Encyclopedia of World Problems and Human Potential is a collaboration between UIA and Mankind 2000, started in 1972. It is the result of an ambitious effort to collect and present information on the problems with which humanity is confronted, as well as the challenges such problems pose to concept formation, values and development strategies. Problems included are those identified in international periodicals but especially in the documents of some 60,000 international non-profit organizations, profiled in the Yearbook of International Organizations.
The Encyclopedia includes problems which such groups choose to perceive and act upon, whether or not their existence is denied by others claiming greater expertise. Indeed such claims and counter-claims figure in many of the problem descriptions in order to reflect the often paralyzing dynamics of international debate. In the light of the interdependence demonstrated among world problems in every sector, emphasis is placed on the need for approaches which are sufficiently complex to encompass the factions, conflicts and rival worldviews that undermine collective initiative towards a promising future.
Non-profit, apolitical, independent, and non-governmental in nature, the UIA has been a pioneer in the research, monitoring and provision of information on international organizations, international associations and their global challenges since 1907.