Trade negotiator: Increasing economic prosperity in a country tends to bring political freedom to its inhabitants.
Conclusion (therefore)
It is wrong for any country to adopt trade policies that are likely to seriously hinder growth in the prosperity of any other country.
Evidence
Increasing economic prosperity in a country tends to bring political freedom to its inhabitants.
Evaluate
The overlapping ingredient between the evidence and conclusion is the concept of "prosperity", so we should focus on the link between the language connected to prosperity.
From the evidence what we know about prosperity is, "tends to bring political freedom to inhabitants".
What we're trying to prove about prosperity is, "shouldn't adopt a trade policy that hinders it".
Goal
Let's look for something like "a country shouldn't adopt a policy that would hinder [something that brings political freedom to that country's inhabitants].
If it's more conditional, then we want a Premise to Conclusion move like,
If X brings political no country's freedom to a → trade policy should country's inhabitants hinder X