Russia has replaced the United States as the largest supplier of arms to Latin American countries. This happened despite the fact post-communist Russia expects to be paid for this stuff. During the Cold War Russia (as the Soviet Union) sold a lot of weapons on credit (with no hassles if you missed payments) in order to gain foreign allies. What Russia offers now is lower prices and greater flexibility (than the U.S. and European nations) in paying bribes. Russia is a popular arms supplier to countries with leftist governments (most Latin American states, especially Cuba, Nicaragua and Venezuela) because these nations still think of Russia as a champion of socialists worldwide. That is no longer the case but Russia plays along if that’s what it takes to get the sale.
Russia is no longer a “socialist state” itself but rather an oligarchy run by a corrupt government that has established a symbiotic relationship between the government and the few dozen families that control most of the national wealth. In other words, not much different that many of the countries in Latin America (even some of the “socialist” ones). Moreover these nations can afford to buy cheaper, less capable Russian weapons because they know the U.S. will protect them from any threats outside the Americas. Locally all they have to worry about is local rebels, angry citizens or neighbors armed as poorly as they are. For that, the cheap Russian stuff gets the job done, even if you have to pay for it.