Sukhum functioned as the capital of the `` Union treaty '' Abkhaz Soviet Socialist Republic associated with the Georgian SSR from 1921 until 1931 , when it became the capital of the Abkhazian Autonomous Soviet Socialist Republic within the Georgian SSR .	<arg1> it </arg1> <rel> became </rel> <arg2> the capital of the Abkhazian Autonomous Soviet Socialist Republic within the Georgian </arg2>	1