Final answer:
Nationalism is the term that best expresses the strong belief in prioritizing the interests of one's own nation-state, promoting its culture and interests above others, and advocating for its unique identity and superiority.
Step-by-step explanation:
The strong belief that the interests of a particular nation-state are of paramount importance is best expressed by the term nationalism. Nationalism is a political ideology that promotes the interests of a nation over international concerns and advocates for the uniqueness and inherent superiority of the individual's own country over others. It emphasizes loyalty, devotion, and a sense of national consciousness that exalts one nation above all others while placing primary emphasis on the promotion of its culture and interests.
This concept often leads to a desire for a people with common cultural or ethnic backgrounds to live independently under their own rule, asserting national interests separately from those of other nations. Nationalism was particularly influential in Europe during the 19th century, playing a key role in the formation of nations out of smaller kingdoms and principalities, and it can also be linked to movements for independence from colonial rule. However, it's important to acknowledge that while nationalism can foster domestic unity, it has also been associated with negative outcomes such as social exclusion, hostility towards outsiders, and even war.