A dual citizen may have acquired citizenship by birth in a foreign country, by descent from a foreign citizen parent, or by naturalisation. Singapore citizens who voluntarily and intentionally acquire citizenship of a foreign country after the age of 18 may be deprived of their Singapore citizenship by the Government.[8] Foreigners who naturalise as Singaporean citizens are required to renounce all foreign citizenships.[9] Persons who are born outside of Singapore and have at least one parent who is a Singapore citizen may register with a Singapore consulate within a year to acquire Singapore citizenship by descent. However,such persons must renounce their foreign citizenship, if any, before reaching22 years old. The Constitution of Singapore is silent on a Singapore citizen who acquired citizenship by birth and is a foreign citizen by descent. So long as such a person refrains from exercising his rights of the foreign citizenship, the Government has no grounds to deprive him of his Singapore citizenship and he may hold on to dual citizenship.[10]
The prohibition of dual citizenship is a contentious issue in Singapore. As the economy becomes more globalized and Singaporeans more mobile, many Singaporeans have acquired foreign citizenships and reluctantly renounced their Singaporean citizenship even though they may feel a strong emotional attachment to Singapore. Immigrants who have been resident in Singapore for long periods and qualify for Singaporean citizenship may be reluctant to become naturalized citizens as it would mean giving up the citizenship of their native countries.
The government's rationale for not allowing dual citizenship is that Singapore is a young and vulnerable nation which cannot afford to allow its citizens multiple allegiances which may be compromised in times of national crisis. Citizens without a second citizenship may feel aggrieved if dual citizens enjoy the benefits of citizenship during periods of wealth but leave the country in trying times.[11] Nevertheless, the government is open to the possibility of allowing dual citizenship if local and global circumstances demand so.[12]