The Yalta bargain for Soviet entry against Japan

Did the United States give substantial ground at Yalta to secure Soviet entry into the war against Japan?

Yes. The concessions were substantial and, in hindsight, regrettable.

The United States gave way on a fair amount at Yalta to secure Soviet entry into the war against Japan. In hindsight, those concessions are described as regrettable. The settlement's individual terms are not discussed here. The focus is the diplomatic price paid for Soviet participation.