The rule of granting citizenship to all born in Ireland is less restrictive than provisions elsewhere, writes Carol Coulter
The laws governing nationality are deeply embedded in the historical experience of individual states.
Nowhere is this clearer than in comparing, on the one hand, countries with a long constitutional history and a positive experience of immigration with, on the other, recently established states which experienced effective colonisation.
Thus, in the US any child born there is entitled to US citizenship, although this does not automatically guarantee the right to residency until the child attains the age of majority. On the other hand, the Baltic states tend to restrict the right to citizenship to those born to the descendants of those who were citizens prior to the states' annexation by the Soviet Union after the second World War.
Others (and clearly the authors of their constitutions and laws had Russian nationals in mind) have high hurdles to cross to attain citizenship by naturalisation. These include demonstrating their knowledge of the local languages of the relevant Baltic state, familiarity with their history, laws and constitution, and declarations of loyalty.
Even among the existing member-states of the EU the requirements for obtaining citizenship vary greatly. Two contrasting principles are at work: jus sanguinis, which grants nationality according to descent, and jus soli, which grants it according to law or regulation, normally permitting naturalisation. All states combine both to some degree.
The closest regime to the current Irish one is what pertained in the UK before 1983, when the 1981 British Nationality Act came into force.
British nationality included the right to reside in the UK and was available to those born in the former British Empire as well as those born in the UK. However, the 1981 Act distinguished between British subjects entitled to reside in the UK and those who are not.
In order to acquire British nationality now, a person must be born in the UK with one parent either a citizen or permanently resident, or to a British citizen living abroad. Naturalisation is available to those over 18 who have lived legally in the UK for five years and have sufficient knowledge of English, Welsh or Scots Gaelic.
The only state, other than the UK and Ireland, which granted citizenship automatically at birth until recently was Malta. That was changed in 1989, and since then any non-national who wishes to become a Maltese citizen must have lived there for five years.
Linguistic knowledge is a feature of nationality law in a number of countries. This is most notable in Portugal, where a person seeking naturalisation can do so after six years' residence if the official language of their parent state was Portuguese. They must live in Portugal for 10 years before applying for naturalisation if it was not.
All EU states require some period of residence before a non-national can apply for naturalisation. This varies from one year in Spain to 10 in Portugal for those whose native language is not Portuguese.
In Denmark and Greece 10 years' residence is also required; in Germany a child born to parents resident for eight years is automatically a citizen; while in many other countries a child born in the state can apply for citizenship when he or she becomes an adult, provided they have been resident there for a number of years.
In the accession states also there is no uniformity. Many of them only came into existence as independent states, or re-established their independence, within the past 15 years, after decades under the influence of the Soviet Union.
Nationality is based either on descent or place of residence at the time the state was established, although they allow for naturalisation. Nationality is, in the cases of those countries with a history of emigration, also granted to emigrants and their descendants. Most, though not all, of the accession states frown on dual nationality.