To other readers, perhaps especially those political scientists who are now so interested in drawing general rules about "world systems” or the recurrent pattern of wars, this study may offer less than what they desire. To avoid misunderstanding, it ought to be made clear at this point that the book is not dealing with, for example, the theory that major (or “systemic”) wars can be related to Kondratieff cycles of economic upturn and downturn. In addition, it is not centrally concerned with general theories about the causes of war, and whether they are likely to be brought about by "rising” or "falling" Great Powers. It is also not a book about theories of empire, and about how imperial control is effected (as is dealt with in Michael Doyle’s recent book Empires), or whether empires contribute to national strength. Finally, it does not propose any general theory about which sorts of society and social/governmental organizations are the most efficient in extracting resources in time of war.