Demographic indicators in South Korea have remained stably low for several decades, which determines the emphasis on measures aimed at increasing the birth rate. In this article, the demographic situation is considered as a social problem. The author discusses the motives, results, and limitations of the current demographic policy, as well as the opinions of researchers on the policy in the field of interethnic marriages according to English historiography. This article shows that Korean society is rapidly becoming a multicultural society and this process is inevitable and irreversible. In support of this argument, the article considers various social factors that contribute to the creation of a multinational Korea, including the rapid aging of the population, low birth rates and a shortage of brides. The Korean case suggests the need for a paradigm shift in understanding multiculturalism.