Citizenship, O’Neil writes, is “an individual’s relationship to the state, wherein states swear allegiance to that state and the state in return is obligated to provide rights to those citizens.” Each state has the right to determine the basis upon which individuals-residents and non-residents alike–fulfill the requirements of citizenship. (Indeed, the extent of citizen obligations also varies from state to state.) As you know, there are three ways in which citizenship can be acquired: jus soli (birth on the territory of the state), jus sanguinis (on the basis of blood relations), and naturalisation.
Prior to changes in its citizenship law in the late 1990s, Germany was a state that based its citizenship law almost exclusively on jus sanguinis. That is, if one were (considered to be) a part of the German nation (“folk”), then one could relatively easily acquire German citizenship, even if they were not born on the territory of the modern German state. Conversely, even those who were born in Germany (and whose parents had also been born and raised in Germany) but were not nationally (or “ethnicity”) German could not obtain German citizenship. A vivid example of the impact the recent changes in German citizenship law have had on German society comes from international soccer (football, really!) where we can see the rosters of two respective German national teams. One of these rosters is the starting lineup for the 1974 World Cup Final (West Germany defeated the Johan Cruyff-led Dutch 2-1 in Munich), while the second is Germany’s starting lineup for the 3rd-place game (Germany defeated Uruguay 3-2) at this past summer’s World Cup held in South Africa. Which one is which? (Note, in order to be eligible to play for an international match for a country, the player must be a citizen of that country,)
N.B.: If you are a soccer fan, you’d be able to distinguish which roster belongs to which year on the basis of the position names (DM,, RW, AM, FW, etc.) alone! Soccer tactics sure have changed a bit over the last few decades!