Why didnt Truman keep on doing land invasions instead of making the decision to drop the bomb?

President Truman opted not to continue land invasions primarily due to the anticipated high casualties and extended duration of such campaigns, particularly in light of Japan's fierce resistance. Estimates suggested that an invasion could result in hundreds of thousands of American lives lost, alongside significant Japanese civilian and military casualties. The use of atomic bombs on Hiroshima and Nagasaki was seen as a means to expedite Japan's surrender and ultimately bring a swift end to World War II, thereby saving lives in the long run.