You can order Great Powers from Amazon.com. You will find it a compelling and provocative read. Part of the attraction of an excellent read is in the challenge to assumptions it provides. I part company with Dr. Barnett on his assessment of Iran –to be specific, his optimism that Iran 2009 is very similar to the U.S.S.R. mid-80s.
But if you can’t read and refute his case, you have no basis arguing for a hard line against Iran. The difference is between the desire of the elite of an avowedly secular state to preserve itself and the destabilizing fact of a theocratic elite’s indifference to suicide in the service of religious fanaticism.
Barnett argues that the threat of the latter is overblown. Perhaps it is, and he is a skilled proponent of that view. If you are confident of your arguments, give him a shot to persuade you otherwise.