In OTL Tannu Tuva was established by a combination of the Bolshevik troops taking control of Tuva, and the Tuvans declaring independence from Russia (having been acquired from China). The entity created in August 1921 was called Tannu Tuva until 1926, and was absorbed into the USSR in 1944, and is now known as Tyva Republic within the Russian Federation. Its capital Kyzyl was the most remote in the world (title now held by Ulan Bator), and the state was most notable for its stamps, of which several were diamond-shaped and triangular, and all being produced in Moscow. It was the third persisting Communist state - after its neighbours, the USSR, and Mongolia.
In the alternative history variant, Tannu Tuva retained a degree of autonomy and negotiated with its neighbours: at times it served as a place of exile - due to its remoteness and lack of railways. It also negotiated with the Czechs occupying the Trans-Siberian Railway, and encouraged the peoples of Soviet Asia to resist Stalin's depredations.
After the break up of the USSR, Tannu Tuva decided, in view of its central position in Asia, and its limited resources, to develop as an entrepot trading hub of Central Asia; it also provides a convenient base for Asian regional organisations.