How are treaties backbone of international trade?

If we didnt have peace treaties, operation treaties, trade treaties, then we would all be fighting and we would be putting bombs in the shipments to and fro other countries. the treaties are saying....blah blah blah we promise to be nice to your country and you promise to be nice to our country if we trade with eachother. you will defent us we will defend you...blah blah blah..