Loyalty to one's country or to people with a common language, religion, and history is known as

militarism.

nationalism.

mobilization.

conscription.

I believe the answer is: nationalism

The concept of nationalism promote the love of one own's country, and put the the things that benefited our own country first before we pay attention to the benefit of other country. This often used as a political ideology by parties in order to obtain support from the voters during the election.

Loyalty to one’s country or to people with a common language, religion, and history is known as "nationalism", since in this case people are ascribing a sense of purpose to the "nation" itself.