The Peace of Westphalia ended the Thirty Years' War, which had caused catastrophic human and material losses in central Europe, especially Germany. Millions had died, and Europe would not see a larger general war until the Napoleonic conflicts at the end of the 18th century and the First World War (1914-1918). The Thirty Years' War had been fought partly over the rival ambitions of dynastic families, and partly over religion. It originated as a conflict over the balance of Protestant and Catholic states in the Holy Roman Empire - an issue dating from the adoption, almost a century prior, of the principle that the local ruler could determine which religion should be practiced. Over time, as ruling dynasties changed or died out through marriage, succession, or death, Protestant areas were threatened with re-Catholicization.

The war also involved an effort to contain the power of the Hapsburg dynasty in central Europe and its claim to universal monarchy. Hapsburg generals had won major victories in the early part of the war, but Swedish intervention on the Protestant side turned the tide for a time, until the pendulum swung in the other direction and the Protestant princes, exhausted by war, concluded a compromise peace with the empire in 1635. However, it was at this point that France directly intervened in order to roll back, or at least contain, Hapsburg gains. The war dragged on, stripped of its initial religious justification, for another 13 years. The Peace of Westphalia, a massive and complex diplomatic achievement, ushered in a new era in international relations.

The Peace of Westphalia was itself an innovation. For the first time, a peace treaty was written by representatives from all parties, rather than just a few. Thousands of diplomats helped draft it. The Peace of Westphalia thus established the precedent of a diplomatic congress, which has remained a model for diplomacy until today. After 1648, a new state system emerged in Europe (as well as a new constitutional structure in the Holy Roman Empire). The principles that governed this state system predominated until the late-18th century. There were two primary kinds of states in this period - republics and absolute monarchies - but virtually all states accepted the principles of the new state system. Two principles were particularly important: the principle of sovereignty and that of raison d'état, or "reason of state." (Are present-day international relations governed by diplomatic congresses? What are the strengths and weaknesses of such a system?)

What Did These Principles Mean?

Sovereignty meant the state was the ultimate authority over a given territory and all its inhabitants. State power could be represented by a king, by a parliament, or by a bureaucracy of state officials. The state itself had come to represent a public legal power that existed apart from the person of the king.

Closely linked to the principle of sovereignty was the principle of reason of state, which placed the interests of the state above all other considerations, even morality or religion (recall Catholic France's intervention against the Hapsburgs on behalf of Protestant Germany). Both the internal warfare of the state, and its fortunes in the outside world, became paramount. Reason of state was often a concept used to justify territorial expansion. (Can you think of examples where "reason of state" is invoked today?)

The Prussian king, Frederick the Great (1712-1786) is a good example of a ruler who governed according to the new reason-of-state principle. Frederick was a polished intellectual and political writer. His Anti-Machiavel (1740) was a work that advocated morally inspired politics. But Frederick did not hesitate to become a ruthless conqueror when it was in the interest of Prussia. In 1740, for instance, he invaded the neighboring province of Silesia and cited reason of state to justify his conquest. Such ruthless acts of aggression were common in the era of the new state system.

International affairs in the 18th century, however, were not without restraining principles. The state system was governed by the idea of a balance of power, which held that international order could only be maintained if all of the major European states were kept in equilibrium. But the idea of the balance of power also suggested that if a clearly dominant power arose - "hegemonic" was the traditional term used to describe such a power - other countries would form a coalition to restrain it. Different observers have noted that sometimes the balance of power functioned like an automatic machine: through self-interest countries would seek out allies to prevent any one power from becoming dominant. Other interpreters have suggested that preserving the balance required considerable effort. Some commentators implied that the balance of power acted as a deterrent to prevent war, but others accepted that it might require war to restore the balance of power.

While the idea was widely invoked, it could predict few actual outcomes. In the 17th and 18th centuries, the balance of power suggested that alliances would be short-lived and shifting, arising as required. From the late-17th century to the death of Louis XIV, the balance of power usually involved a coalition of powers gathering to oppose French ambitions. No state felt it could afford to operate alone in such a conflict, and most were constantly negotiating either to secure allies, or to be promised subsidies or new territories for becoming allies. Thus, even if the balance of power advanced equilibrium, it also produced a pervasive feeling of insecurity and continuing preoccupation with the self-interest of each state; with reason of state, which elevated the interests of the state to the highest value of politics; and statecraft. (Does the principle of "balance of power" govern international relations today?)

The principle of balance of power was most famously used to restrain the ambitions of King Louis XIV of France. Louis ruled from 1643 to 1715, and under him France became the superpower of its day, constantly trying to expand its territory. To restrain him, the other European powers formed military coalitions. For example:

In the War of the League of Augsburg (1689-1697), England, the Dutch Republic, and several German states fought to keep France from conquering large parts of Germany that were adjacent to the French frontier.

In the War of the Spanish Succession (1701-1713), England, the Dutch Republic, German states, Austria, Prussia, and Portugal all formed a grand alliance to keep the Spanish royal line from switching from the Hapsburgs to the Bourbons, which, it was feared, would make Spain and its possessions a tool for French interests. The alliance could not finally keep Louis XIV's grandson from inheriting the throne, but it did compel Spain to give up its major European territories outside Spain (the Spanish Netherlands and southern Italy). When this war ended with the Peace of Utrecht (1713), France had lost some of its American colonies and had been prevented from expanding into the Low Countries and Germany. Spain no longer had strategically placed domains on the English Channel or in Italy. England and Austria gained territory, and the Prussian prince gained the title of king. For several decades, the rest of Europe feared that Louis XIV's France would dominate the entire continent. Coalitions and wars, however, restored the balance of power.

Another concept important to the state system was the principle of "dynastic legitimacy." A dynasty in the early modern period was a family that ruled a state by virtue of an inherited right. The principle of dynastic legitimacy justified most regimes up until the late-18th century, when the idea of "popular sovereignty" became common. This meant that international politics and wars revolved around a few families. Louis XIV's famous claim, "L'état, c'est moi" ("I am the state"), reflects the importance of the royal figure as the representative of the state. Dynastic legitimacy meant that when no male heir survived the death of a king, bloody succession crises often followed. The War of the Spanish Succession (1701-1713) and the War of Austrian Succession (1740-1748) are notable examples.

Underlying Conditions of the State System, 1648-1770

The new state system did not emerge within a vacuum. Particular economic and social conditions affected its development.

In eastern Europe, roughly defined as the area east of the Elbe River (in the middle of modern Germany), state economies and armies were supported by peasant labor. Peasants, or serfs, were tied to the land, providing both agricultural labor and drafted soldiers for aristocrat-led armies. Prussia's military might, for example, was built on serf labor. The local noble landlord, the Junker, had the responsibility of raising soldiers from the villages in his region. Towns had to pay heavy taxes and provide material to support these forces. The Prussian bureaucracy devoted much effort to mobilizing human and material resources for maintenance of an army.

In western Europe, state economies were more highly developed, and peasant labor could not simply be pressed into military service. Governments used tax revenues to hire captains who recruited paid soldiers. A general "draft," or conscription, came into use in western Europe only in the era of the French Revolution. Armies were also supported indirectly, through commercial surpluses based upon trade with far-flung colonial empires. Some Western powers (England and Holland in particular) developed sophisticated financial organizations as well. Joint stock companies allowed investors to pool wealth for business and trading ventures. Central banks (e.g., the Bank of England, founded in 1694 - later a national bank, then a private monopoly granted to shareholders who were willing to finance government needs) allowed some states to borrow vast sums from their subjects (the origin of a national debt). England's great military asset was not a large army - although it did raise armies as war required - but a preeminent navy, as well as the capacity to subsidize its continental allies (such as Prussia in the Seven Years' War). This capacity rested on the most advanced financial system in the world. The Bank of England provided security such that loans could be raised, and the English upper classes - peers and gentry - accepted heavy taxing to fund national defense. (In contrast, the French nobility claimed immunity from major taxes.)

So military financing differed between eastern and western Europe. Warfare was recurrent and pervasive during the era of the new state system. Individual wars, however, were somewhat less destructive than in the 17th century. Sieges and slaughters of civilians diminished. In the 19th century, diplomacy would more effectively secure the balance of power, but in the 18th century, balance of power was chiefly secured through continuous warfare. England and France, for instance, were at war for about 56 years between 1688 and 1815. States fought until they were militarily or financially exhausted. They would then trade territory in Europe or in their colonies, settling an uneasy peace until the next war. The requirements of 18th-century warfare required a great expansion in the size of European armies. The table below reflects that expansion of soldiers in the first half of the 18th century.

















The average standing army in the 16th century stood at about 15,000 soldiers. In the 18th century, this average rose to approximately 150,000 soldiers. Wars were less costly and devastating in the age of the state system than they had been during the wars of religion, or than they would be during the 20th century. But war was a more continuous fact of life during this time. Traditional European armies had depended on aristocratic commanders, small paid forces and mercenaries. But these armies were not particularly large or effective, and (because they supported aristocratic power) posed potential challenges to royal power. New professional armies were therefore formed, and this cost a great deal. Prussia, for instance, spent 90% of its budget supporting its standing army. By the middle of the 18th century, France was so burdened with the costs of war that 60% of all income went to pay the interest on the state debt. (Why was war so constant during the 18th century? What factors have made full-scale war less common but more bloody in the 20th century?)