So we can go with a mix of trade and protectionism, which has been proven to build a nations economy multiple times, or we can risk it and go with what economists assure us works even better?

And do their assurances only work if everyone adopts unbiased free trade, and break down when a group favors its own, such as shown in http://jasss.soc.surrey.ac.uk/16/3/7.html ?