There was a faction of right wing Republicans who wanted to end the war quickly in order to forestall Russia, but they wanted to end the war quickly by forgoing an invasion and allowing Japan to surrender conditionally, without an occupation or a forced change of government or constitution, because they thought an armed and relatively intact militarist-run Japan would be a good buffer against the Soviet Union. This was unacceptable to the liberal new deal faction running the US government, who believed that a disarmed and democratic Japan was the only way to prevent another war.

“They only wanted to keep the commies out” is a nicely glib line, but one that glosses over the many, many political considerations that shaped the end of the pacific war and reveals an almost total ignorance of the scholarship on the subject