Generally speaking, when the USSR intervened militarily in areas of Asia adjacent to the USSR, while it may have attempted to set up "friendly" governments there (the temporary support of Kuchak Khan's Gilan Soviet Republic in northern Persia, the creation of the Mongolian People's Republic in the 1920's, the Ili Rebellion in Xinjiang in the mid-1940's, the Azerbaijan and Kurdish "autonomous" governments in Iran in 1945-6) it did not try to incorporate those areas into the USSR, except for Tuva (and Tuva was a special case, not only because it had been a Russian protectorate but because it bordered only the USSR and Outer Mongolia). The Soviet military intervention in 1928-9 was simply an inept attempt to restore the Soviet-friendly Amanullah
https://www.alternatehistory.com/fo...-during-the-early-1920s.446617/#post-17229196 and not even to establish a Communist regime in Afghanistan, let alone to incorporate the country into the USSR Even so, the intervention (with Soviet troops disguised as Afghanis) drew sharp criticism even from nations like Iran and Turkey that sympathized with Amanullah's reforms. Even had the intervention succeeded, it is hard for me to see the USSR incorporating Afghanistan--which as I noted was nor the purpose of their (limited) intervention and would have been contrary to their practice elsewhere in Asia.