Question

What is the most likely reason why the United States would send military aid to countries controlled by dictators?

to help bring an end to protests
to stop a larger enemy or threat
to allow dictators to gain control
to take control of the government

Answer 1

to stop a larger enemy or threat

Historically the U.S. has provided military aid to authoritarian regimes when those regimes were seen as allies against a greater threat (for example, to counter Soviet influence during the Cold War or to fight terrorism), not primarily to help dictators suppress protests or to seize control itself.