I've mentioned before on this forum that I've spoken with several Soviet veterans of their Afghan war. They were shocked at the resolve of Afghans, and told me they didn't think any foreign occupier could ever defeat them.

About 600,000 Soviet soldiers served in that conflict for over 9 years.

The total irrecoverable personnel losses of the Soviet Armed Forces, frontier and internal security troops came to 14,453. Soviet Army formations, units and HQ elements lost 13,833, KGB sub-units lost 572, MVD formations lost 28 and other ministries and departments lost 20 men. During this period 417 servicemen were missing in action or taken prisoner; 119 of these were later freed, of whom 97 returned to the USSR and 22 went to other countries.

Yeah, wiki, my friend:

Soviet war in Afghanistan - Wikipedia, the free encyclopedia