To make a strong argument, the writer or speaker must avoid logical fallacies.
This is because a fallacy is something that is untrue, thus if it was logical your reader might be persuaded against your argument. Basically, as a writer you don't want to contradict yourself and you only want to support one side of an argument.
Hope this helps! :)
The answer to this would be true
Here is the answer to the given question above. Based on the given sample sentences, the best way to combine the sentences using a semicolon would be this: <span>The world’s nations must cooperate; one nation cannot solve the world’s problems by itself. The correct answer would be the second option. Hope this helps.</span>