[iso1631]

British Empire was heavily involved in Europe, North Africa and South-East Asia. Events in India had great consequences on Europe

The USSR on the other hand barely had any involvement in the Pacific theatre, entering in August 1945.

[AnimalMuppet]

The USSR had to carefully keep enough land forces in the Pacific region to deter a Japanese land invasion. (Remember that Japan controlled Manchukuo.) So, yes, the USSR had little involvement, and they had to be very careful to keep it from becoming an active front.

See https://en.wikipedia.org/wiki/Battles_of_Khalkhin_Gol (that was in 1939).

[dwd]

Fear of the USSR entering the war against them was also a deciding factor in Japan's surrender. More so than the atomic bombs.