The European states emerged in the midst of struggle and strife, and struggle and strife have continued to characterise their existence. Yet, in early modern Europe it was no longer the competing claims of local and universal authorities that had to be combated but instead the competing claims of other states. The Thirty Years’ War, 1618–1648, was the bloodiest and most protracted military confrontation of the era. As a result of the war Germany’s population was reduced by around a third. What the Swiss or the Scottish mercenaries did not steal, the Swedish troops destroyed. Many of the people who did not die on the battlefield died of the plague. The Thirty Years’ War is often called a religious conflict since Catholic states confronted Protestants. Yet, Protestant and Catholic countries sometimes fought on the same side and religious dogma was clearly not the first thing on the minds of the combatants. Instead the war concerned which state should have hegemony (or dominance) over Europe. That is, which state, if any, would take over from the universal institutions of the Middle Ages. The main protagonists were two Catholic states, France and Austria, but Sweden – a Protestant country – intervened on France’s side and in the end no dominant power emerged.
The Treaty of Westphalia, 1648, which concluded the 30 years of warfare, has come to symbolise the new way of organising international politics. From this point onwards, international politics was a matter of relations between states and no other political units. All states were sovereign, meaning that they laid claims to the exclusive right to rule their own territories and to act, in relation to other states, as they themselves saw fit. All states were formally equal and they had the same rights and obligations. Taken together, the states interacted with each other in a system in which there was no overarching power. Sovereignty and formal equality led to the problem of anarchy. Within a country ‘anarchy’ refers to a breakdown of law and order, but in relations between states it refers to a system where power is decentralised and there are no shared institutions with the right to enforce common rules. An anarchical world is a world where everyone looks after themselves and no one looks after the system as a whole. Instead, states had to rely on their own resources or to form alliances through which the power of one alliance of states could be balanced against the power of another alliance. Yet, as soon became clear, such power balances were precarious, easily subverted, and given the value attached to territorial acquisitions, states had an incentive to engage in aggressive wars. As a result, the new international system was characterised by constant tensions and threats of war – which often enough turned into actual cases of warfare.
At the same time various practices developed which helped regulate common affairs. The foremost example was the practice of diplomacy as exemplified by the way peace treaties were negotiated. From the seventeenth century onward, European states met after each major war in order to reach a settlement and lay down the terms of their future interaction. These diplomatic practices had their origin in relations between the city-states of northern Italy. Once these states had made themselves independent both of the pope and the emperor, they soon discovered that their relations had become vastly more complicated. In order to avoid misunderstandings and unnecessary conflicts, the different rulers began dispatching ambassadors to each other’s courts. This diplomatic network provided a means of gathering information, of spying, but also a way of keeping in touch with one another, of carrying out negotiations and concluding deals. The practices of diplomacy soon expanded to include a number of mutually advantageous provisions: the embassies were given extraterritorial rights and legal immunity, diplomatic dispatches were regarded as inviolable and ambassadors had the right to worship the god of their choice. These originally north Italian practices gradually expanded to embrace more states and by the middle of the seventeenth century the system included France, Spain, Austria, England, Russia, Poland, Denmark, Sweden and the Ottoman Empire. Diplomatic practices were never powerful enough to prevent war, indeed wars continued to be common, but they did provide Europeans with a sense of a common identity. A European state was, more than anything, a state that participated in the system of shared diplomatic practices.