This is what Theodore Hall said on CNN in 1998.
“I decided to give atomic secrets to the Russians because it seemed to me that it was important that there should be no monopoly, which could turn one nation into a menace and turn it loose on the world as ... as Nazi Germany developed. There seemed to be only one answer to what one should do. The right thing to do was to act to break the American monopoly.”
It seems that I remember this guy on some PBS program about homegrown atomic spies.
"We knew that we had created a new means of warfare, and the question as to what nation, to what victorious nation we were willing to entrust this brainchild of ours was a moral decision more than anything else. We wanted to see the world spared another conflict such as Germany had just been through, and we felt that only by surrendering such a weapon to people who are guided by the Bible could such an assurance to the world be best secured."
"We knew that we had created a new means of warfare, and the question as to what nation, to what victorious nation we were willing to entrust this brainchild of ours was a moral decision more than anything else. We wanted to see the world spared another conflict such as Germany had just been through, and we felt that only by surrendering such a weapon to people who are guided by the Bible could such an assurance to the world be best secured."