Technological gains
Our knowledge of other countries and their technology will decline with isolationism. If we don’t converse with other nations and learn about them we will not be able to understand them. We won’t know about their technology. Imagine with me that you are an inventor. If you can’t figure out how to do some thing, you can look at a similar invention and figure it out. Without seeing the invention, you can not figure it out. We will not be able to improve our technology without seeing other technologies.
Subversive Ideas that We Find Unpleasant
If you see someone eat dirt, does that make you want to eat dirt? Of course not! The same thing goes for subversive ideas that we find unpleasant. If we find it bad would we want it? Of course we wouldn’t.
Duty to Intervene
Without interfering in world affairs, we will not be able to help other countries, who have been invaded, or are unhappy with a corrupt government. Imagine with me that you are living in a dictatorship. Another country invades your country and changes the government. Now life is much better. The U.S. has a duty to intervene and help our fellow countries.