Soviet forces already had amphibious experience, including operations in the Baltic. That experience did not yet amount to the ability to mount the very large operation being imagined against Japan. A hypothetical alternative has British and American ships, operated by their own crews, carry Soviet troops after an Allied landing has opened the front. The forces could then divide responsibilities ashore while the maritime allies coordinated the shipping. This is a proposed arrangement, not an account of an invasion that took place.
Notable Point · 2:44:09-2:45:21
Soviet landing experience and the scale of a Pacific invasion
Prior Soviet coastal operations are distinguished from the lift and coordination needed for the hypothetical invasion of Japan.