This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book helps to confirm and strengthen the growing 'thoughtful opposition' in the United States and abroad to the George W. Bush policies, and as such deserves to be taken very seriously. The Bush administration and its defenders agree with opponents that there are risks no matter what is done or not done in regard to Saddam Hussein. An attack against Iraq that succeeds in overthrowing him, particularly if it is not authorized by the UN Security Council, may be attended, the Bush administration concedes, by some unwelcome consequences. The book makes clear that a fundamental issue underlying the entire debate over Iraq policy is conflicting assessment of risk. It is concerned with the importance of the existing international system, including the United Nations.