What concept describes intense loyalty to one's country?

The concept that describes intense loyalty to one's country is nationalism. Nationalism emphasizes a strong identification with one's nation and culture, leading to a sense of pride and devotion to the nation-state. This can manifest in various ways, including a desire for national sovereignty, the belief in the superiority of one's nation, and a commitment to the shared identity and goals of the people within that country.

Nationalism can be a powerful force, often rallying citizens around a common cause or identity, especially during times of conflict or societal change. It is distinct from patriotism, which is generally understood as love for one's country and support for its values and practices, but not necessarily as intense or exclusive as nationalism.

While altruism relates to selfless concern for the well-being of others and collectivism emphasizes group goals over individual ones, these concepts do not specifically pertain to loyalty to one’s nation in the way nationalism does.