Why is patriotism a moral norm?

Love for the Motherland has always been considered one of the highest moral standards. A brave soldier who defends his homeland to the last drop of blood. A mother who instills in her children from childhood love for the Motherland. An ordinary customer who supports a domestic manufacturer. These actions speak equally loudly about patriotism. Of course, patriotism should not go beyond common sense. I believe that a patriot is not the person who hung the national flag at home. A patriot is a person who loves his Motherland and works for the benefit of its prosperity.