If world war III is happened then the earth is lost by nuke weapons. So therefore world war III by using media outlets, news. They debate each other for more relevant issues. Then its called a word war or also known as the word war III. It is happening now because of climate change issues.
I always believed that first of all the war is political, then economic, and then physically destroy each other. If you follow this rule, then the first two facts work. The last one remained. But the first question will be who will start a war against whom and against whom. Today there are small local conflicts. But it can be small parts of a large whole.