The Western powers followed a policy of appeasement despite the fact that it encouraged aggression because these countries were trying to avoid another World War at all costs. Countries like Great Britain and France were heavily involved in World War I and suffered severe infrastructure damage. It took years for these countries to rebuild to their previous state. The last thing they wanted to do was get involved in another war that would ruin their countries infrastructure and result in the loss of thousands of soldiers.
To be on ppf, the conditions that must hold true will be something like :
- Factors of productions must have increasing returns
- The amount of labor will be similar to the amount of responsibilities.
- There should be capital growth
I believe it's Slaves because they came from Africa.