Question

The simplest way for countries to enter into a trade agreement is through signing a treaty to enter a
with another country.

are outside groups that help countries to solve trade disputes.
A
is a specific territory that is governed under different economic laws and restrictions.

Answer 1

1) free trade agreement (or bilateral trade agreement) — a treaty between two (or more) countries to reduce trade barriers.
2) arbitrators (or mediators/third parties) — outside groups that help countries resolve trade disputes.
3) special economic zone (SEZ) (or free-trade zone) — a specific territory governed under different economic laws and regulations.