A note on the Atomic Weapons. Although, all he did was inform the president that such a weapon could be built, without knowing that one was possible, they wouldn't have tried to build one so he was directly responsible in that respect.
He also didn't fail on unification, he simply didn't have the time to finish it. That's not to say that he didn't fail. He considered his letter to president Truman regarding E=MC^2 is greatest failure after the weapon was deployed. Also note that he was invited to work on the A-bomb, but refused to play any part in masterminding such a weapon.
