Jus sanguinis
Today, almost all states apply some combination of "jus soli" and "jus sanguinis" in their nationality laws to varying degrees. Historically, the most common application of "jus sanguinis" is a right of a child to his / her father's nationality. Today, the vast majority of countries extend this right on an equal basis to the mother. Some apply this right irrespective of the place of birth, while others may limit it to those born in the state. Some countries provide that a child acquires the nationality of the mother if the father is unknown or stateless, and some  irrespective of the place of birth. Some such children may acquire the nationality automatically while others may need to apply for a parent's nationality. Modern development. At the end of the 19th century, the French-German debate on nationality saw the French, such as Ernest Renan, oppose the German conception, exemplified by Johann Fichte, who believed in an "objective nationality", based on blood, race or language. Renan's republican conception, but perhaps also the presence of a German-speaking population in Alsace-Lorraine, explains France's early adoption of "jus soli". Mixed standards. Many nations have a mixture of  jus sanguinis and "jus soli", including the United States, Canada, Israel, Greece, the Republic of Ireland, and recently Germany. Today French nationality law narrowly applies "jus sanguinis," but it is still the most common means of passing on citizenship in many continental European nations. Complications due to imposed boundaries. Some modern European states which arose out of the dissolved Austro-Hungarian or Ottoman empires have huge numbers of ethnic populations outside of their new 'national' boundaries, as do most of the former Soviet states. Such long-standing diasporas do not conform to codified 20th-century European rules of citizenship. In  many cases, "jus sanguinis" rights are mandated by international treaty, with citizenship definition imposed by the national and international community. In other cases, minorities are subject to legal and extra-legal persecution and choose to immigrate to their ancestral home country. States offering "jus sanguinis" rights to ethnic citizens and their descendants include Italy, Greece, Turkey, Bulgaria, Lebanon, Armenia, Hungary and Romania. Each is required by international treaty to extend those rights. Current "Leges sanguinis" states. Many countries provide citizenship on preferential terms to individuals with ethnic ties to these countries (so-called "leges sanguinis").