Wars doesnt harm every country. i think some of the country gets benefited because of it.
If you are talking in terms of power and money, you may be right, but in terms of ethics and human rights I don't think it benefits anyone.
And, as we've seen with Covid-19, globalization has broken the natural boundaries that always existed between countries/continents, so nowadays any war impacts every country in some degree. I don't know where you live, but chances are that you have witnessed it yourself the last time you went to a supermarket.