The Soviets were quite gunshy about backing internecine conflicts, having been drawn against their will into both Cuba and Yugoslavia. A large part of why the Soviet Union collapsed is the amount of resources they were forced to pour into both countries, even to the point of providing free education and training to Cubans and Yugoslavians on Moscow’s dime, propping up those countries’ infrastructure even while the Soviets’ own was crumbling. To this day, Cuba has some of the best doctors in the world as part of some of the most comprehensive health care anywhere in the world—all thanks to the Soviets.
Every time the Soviets reached out their hand, they got burned. Afghanistan is another example. Asked for help by Afghanistani communists, the Soviets built hospitals and schools all the while their troops were being fed into a meat grinder hand-cranked by the CIA with massive shipments of weapons to Islamic religious fanatics.
Can you really blame the Soviets for not wanting to get drawn into another similar conflict?