The Soviets conducted many amphibious landings during WW2 including large scale operational. It would not have been something new for them.
No open water coastal landings. Project Hula - Wikipedia https://en.wikipedia.org › wiki › Project_Hula Project Hula was a program during World War II in which the United States transferred naval vessels to the Soviet Union in anticipation of the Soviets ... Why America Gave the Soviets 150 Invasion Ships (Just ... https://nationalinterest.org › blog › reboot › why-ameri... May 25, 2021 — Though the Soviet Navy executed smaller-scale amphibious operations in Arctic, Baltic and Crimean Seas throughout World War II, ... ". . . Though the Soviet Navy executed smaller-scale amphibious operations in Arctic, Baltic and Crimean Seas throughout World War II, their land power never developed the massive and specialized amphibious landing capabilities of the Western Allies. Not only did Soviet ships lack cutting-edge technologies, but they were mostly deployed on the Atlantic-facing side of Russia for the anti-Nazi struggle. If the United States wanted Soviet assistance for an invasion of Japan, it not only needed to pitch in the ships to pull it off, but it would have to train Soviet sailors how to operate them. What happened next is detailed by Richard Russell in his study “Project Hula: Secret Soviet-American Cooperation in the War Against Japan.”. . . "
That's the difference between lightning and a lightning bug. Both those operations were small and supported by overland offensive operations.
Well D-Day was supported by overland offensive operations. Sakalin was not supported by other land forces anymore than Inchon in NK. These were as large as many of our island landings in the Pacific. They had 8 operational size landings so they had plenty of experience and the equipment to have launched an invasion. The Soviet Army was quite the capable force.
Sure it was we dropped a huge force behind enemy lines in an operation to cut off the coastal defenses and delay any reserve forces from moving up. I've wargamed it for decades
Airborne operations are not overland offensives. They are very short term blocking operations. Our D-Day landing in Normandy was significantly beyond Soviet capabilities. And btw, the airborne operations associated with our D-Day landings were also well beyond Soviet capabilities.
They are once they are on the ground. It was the largest airborne operation at the time. The Soviets didn't need a D-Day size although it would have been a substantial force they planned to land. Did Hiroshima Save Japan From Soviet Occupation In the wee hours of Aug. 24, 1945, Soviet long-range bombers would take off from their air base not far from the Far Eastern port of Vladivostok and fly east, across the Sea of Japan, dropping lethal payloads on the northern Japanese island of Hokkaido. At 5 a.m. that morning, two Soviet regiments would storm their way onshore, followed, in two hours, by a larger force. Within days, two infantry divisions would sweep across northern Hokkaido, cutting the island in half. That was the rough battle plan drawn up by the commander of the Soviet Pacific Fleet, Adm. Ivan Yumashev, at the end of World War II for occupying Hokkaido. Troops were on standby. Submarines were ordered to the Hokkaido coast for reconnaissance in preparation for land invasion, and had even started sinking Japanese ships (tragically, just refugee boats fleeing Soviet operations on nearby Sakhalin Island). The Soviets had by then occupied southern Sakhalin and were mopping up the remnants of the Japanese along the Kuril island chain that stretched from Hokkaido to the Kamchatka Peninsula, in Russia’s far northeast. Although the Red Army was not as experienced as the Americans with landing operations, this Soviet “D-Day” in Hokkaido would’ve been a walkover — the Japanese army was in shambles, and Emperor Hirohito had recently proclaimed defeat." https://foreignpolicy.com/2015/08/05/stalin_japan_hiroshima_occupation_hokkaido/ In 1945, the Navy Secretly Handed Over 150 Warships to Russia for an Invasion of Japan ....On April 10, 1945 a Soviet freighter slipped up to a quay at a frozen military base on a remote tip of Alaska aptly named Cold Bay. Inside her were over 500 sailors of the Soviet Navy. The Soviets had arrived to train on the first of 149 vessels the U.S. Navy was transferring to the Soviet Union. That fleet’s secret mission: to transport the Red Army for an invasion of Japan, even while Moscow and Tokyo remained officially at peace.... https://nationalinterest.org/blog/b...over-150-warships-russia-invasion-japan-30892
The Soviets did not have the capability to carry out that operation, and the Japanese were quite a bit stronger than your author understands.
Japan was just looking to become what Brittain and the USA bad already been, an imperial power. They just got into the game too late.