All resources are scarce and for the most part, people in power could dictate who would have a monopoly on a determined part of the market. That is called mercantilism.
It started when kings created lords and these lords would pay taxes to the kings. Fast forward to today, more people are able to get their hands on the means of production without the "blessing" of a lord or dictator. The privatization of land for the most part has worked in a way where people see a need to trade to fulfill their necessities and then they peacefully exchange finite resources.
Think about this: when I go to Whole Foods to buy a gallon of milk, I value the milk more than I value my 5 bucks. Whole Foods is not exploiting me, nor the milk man. I am able to focus my energy and time on work I love and enjoy and I am glad to exchange my finite resources (time and money) for that milk.
The clerk says thank you and i say thank you back. we both are better off than we were prior to that transaction.
take this example to any other aspect of life and you'll see how it becomes easier to trade than to wage war for resources. where there is commerce, there is peace.
the real issue is when we have a lord telling us how we can or cannot trade. when goods do not cross borders, armies do.