Question

The period of the early-to-mid-20th Century saw the United States support banana republics in Central America, countries which could be described politically as

Answer 1

controlled by corporate and military forces.

Answer 2

Unstable ... or under the rule of a dictator ... or both.

The idea of the term "banana republic" is that the small nation is economically dependent on one product (such as bananas) and is typically not truly a "republic."  The term "banana republic" was introduced in 1901 by American author O.Henry to describe Honduras and other Latin American countries that were being exploited by corporations like the United Fruit Company.