There has been a recent spate of compelling works on Westphalia settlement and the nature of international politics. Among the most important is the skeptical argument of Stephen B. Krasner, “Rethinking the Sovereign State Model,” Review of International Studies 27 (December 2001, Special Issue): 17–42 and Derek Croxton, “The Peace of Westphalia and the Origins of Sovereignty,” International History Review 21 (1999), as well as Croxton and Anuschka Tischer’s exhaustive guide, The Peace of Westphalia: A Historical Dictionary (Westport, Conn.: Greenwood Press, 2001). Croxton and Tischer’s coverage is a great help to anyone who wishes to begin to work through the vast historiographical swamp of the Thirty Years War.
Readers might also wish to consult the classic article on the legal meaning of Westphalia written by Leo Gross, “The Peace of Westphalia, 1648–1948.” The article can be found in Gross, Essays on International Law and Organization (Dobbs Ferry, N.Y.: Transnational Publishers, 1984), pp. 3–21. A wonderfully written introductory article is Geoffrey Parker’s “The Thirty Years’ War,” History Today 32 (August 1982): 50–51. A little more detailed but extremely readable is A. W. Ward’s “The Peace of Westphalia,” in The Cambridge Modern History, Vol. 4 (Cambridge: Cambridge University Press, 1996), pp. 395–433.
A very neat classic synthesis for the uninitiated is Charles W. Kegley Jr. and Gregory A. Raymond, Exorcising the Ghost of Westphalia: Building International Peace in the New Millennium (Upper Saddle River, N.J.: Prentice-Hall, 2002).