The best answer in that set would seem to be "compromise." I'm not sure I'd use exactly that term, but it's the best term from the set of answers given. Count Camillo di Cavour was prime minister of the Kingdom of Sardinia, serving under King Victor Emmanuel II. This was a time in history (in the 19th century) when prime ministers were starting to exercise more control of policy than the kings themselves. It was also a time of something that came to be known a "Realpolitik" (a German term), or "realistic politics." So I'd say Cavour was a political realist who chose paths of action that would benefit his overall aims, whether or not they fit some specific ideology or master plan. I suppose "compromise" would be another way of saying that, but I'd prefer to say he practiced political realism.
The radiation left after the war. Along with the many people who died thereafter for many years. This also caused a nuclear war of sorts later on with Russia.