I agree with this statement because when a country isolates themselves they don't really know anything about other countries. How can you trust people you don't know. Trade is a way to spread religion and culture! China spreads it's culture with silk! Japan spreads its culture with food. Korea spreads its culture with its music. Everyone has something different to contribute in trade and it gets put into different countries like a melting pot!
The technologies were only used to observe enemies but as their effectiveness became apparent, both sides started to dismantle what they were using. For example, they shot down the planes that they would see causing more death.
