Why are respectful, good-neighborly relations between countries and peoples so important?

Why are respectful, good-neighborly relations between countries and peoples so important? How do they manifest themselves? Give examples from modern life.

If there was no peace between neighboring countries, then there would not be much in our life. For example: cars, microwave ovens, etc. And people would be constantly at war, and by our time there would be no one left. It would also destroy the environment. Moreover, it is much easier to live in a world of peace. These attitudes about the treaties of the last century are manifested. For example: Russia with Japan.