The Manhattan Project was a well kept secret. It was even kept a secret from VP Harry Truman. If you mean there was opposition to the Nakasaki a-bomb being dropped, okay. But by that time, the invasion of Japan was off the table.
I’m not clear exactly what you mean with the reference to Peter Jennings.
One year on VJ Day Jennings did a program on the dropping of the bomb. He defended Japan’s attack on Pearl Harbor and decried our dropping of the bombs.
The second bomb was dropped because the Emperor insisted he was not going to surrender.
Of course, we could have used the Obama plan and talked about the ending of the war.