What is the difference between the american militia and the regular army ?

Militia is a body of citizens enrolled for military service, called out for drill but serving full time only in emergencies. An army is a body of full time professional soldiers. Militia is a body of citizens enrolled for military service, called out for drill but serving full time only in emergencies.

For contemporary Americans the difference between militia and regular, or “Continental,” soldiers is hard to grasp. Both fought in the war. ... For decades after the Revolution, politicians spouted clouds of hot air on the subject, mostly aimed at denigrating the regular army in favor of the militia.

https://allthingsliberty.com/2013/12/militia-continentals/

cuban communists pressured the soviet union to place missiles in cuba.