Recommended: The Tragedy of Great Power Politics

In foreign affairs, there are liberals and realists. Liberals view foreign affairs from an optimistic ideology that believes that reasonable people can always negotiate successfully, and that there is a better world ahead with world peace. Realists have a darker view that human nature hasn't changed appreciably in the past several thousand years, and so we need to deal with the world the way it really is, not the way we wish it were. John Mearsheimer is a foreign affairs realist (as are Henry Kissinger, Brent Scowcroft, and Zbigniew Brzezinsk), and makes a very good case for this position in his 2001 book The Tragedy of Great Power Politics. As he points out, the evidence of history is heavily on the side of realists and against the liberals. This is quite a readable book, but an important one.