Why was trade so important to the roman republic?

rome, along with almost every civilization in the worlds history cannot create and manufacture all its needed goods so they needed allies to help them do so. also with them trying one of their allies got to close. so close that they took advantage of them and then defeated them thus ruling both their old and new land.

these civilizations were located around fertile rivers, where they could produce an abundance of crops

1775 is your answer hope this