T H E G L O B A L S TAT E O F C I T I Z E N S H I P states charge exorbitant costs for releasing their citizens. Even host countries that oppose dual citizenship for their immigrants often have to permit it in such cases. Overall, fears about dual citizenship have often proven unwarranted in terms of their potential to create integration or interstate conflicts, while international agreements have shifted from preventing to managing multiple nationalities, for example, on potentially conflictual issues like taxation or military service. As discussed in section 1 of this report, dual citizenship has slowly spread as a major liberalisation trend, although the diffusion of this norm still varies across world regions. Renouncing foreign ties The requirement to renounce any foreign citizenship, increasingly a relic from the past, has become the least common requirement for ordinary naturalisation. In a mobile, connected world, many people—not just immigrants—have effective links with more than one country, as part of their family, ancestry, work, studies or lifestyle. Dual citizenship helps people to manage these links, with the right to reside, visa-free travel, diplomatic protection, and often electoral, economic and property rights. Both states and citizens have worked out ways to manage the rights and responsibilities that come with multiple nationalities. Even governments that oppose multiple citizenship on paper often cannot avoid it in practice. For example, states want to maintain links with their own expatriate citizens abroad. Moreover, renunciation can be impossible or unreasonable for immigrants from some countries of origin. Some countries consider citizenship as a perpetual allegiance that individuals cannot revoke; refugees cannot be asked to get permission for renunciation from an origin country where they have been persecuted; states engulfed in armed conflict and civil war cannot issue the relevant documents; and some origin Yet, immigrants can only legally become dual nationals if this is accepted by both their destination and origin countries. As visualised in Figure 3.4, currently almost half of the world’s foreign-born immigrants (47%)—an estimated 125 million people—can become dual nationals because both their country of origin and residence allow for this. Dual citizenship acceptance is especially restricted for migrants in Asia, where only 15% can naturalise while remaining a citizen of their country of origin. The restriction of dual citizenship remains a major obstacle depressing immigrants’ interest in becoming citizens of their new country of residence. 3.4 DUAL CITIZENSHIP ACCEPTANCE IN RESIDENCE-BASED NATURALISATION, BY WORLD REGION, 2024 No. of global migrants (in millions) Share of global migrants that can naturalise with dual citizenship acceptance in both destination and origin countr y 83 M 79 M 269 M 71 M 47% 72% 49% 26 M 15% Europe Asia 63% 9M Africa Oceania 57% Americas Dual citizenship acceptance in residence in origin and destination country YES World NO Source: GLOBALCIT Dyadic Dual Citizenship Dataset, updated with data for 2023 and 2024 | Population data from UN Population Division 23