Clausewitz’s examples in On War are typically limited to the period between the mid-18th and early 19th centuries. For this reason, it is important to review the historical circumstances of his writing to put them into a broader context. The author’s role not only as a military analyst but also as an officer in the Napoleonic Wars makes these details of his autobiography relevant to the context of his book.

First, it is not surprising that Clausewitz thought that “[p]eace seldom reigns over all Europe, and never in all quarters of the world” (40). Early Modern Europe until the mid-19th century was a divided continent fraught with armed military conflict for political and religious reasons, since there was no single authority ruling over it. The devastating Thirty Years' War (1618-1648) involved sectarianism between Protestants and Catholics and a battle for dominance between the key European dynasties. According to some estimates, the death toll from combat, disease, and starvation was unprecedented for Europe.

The Treaty of Westphalia (1648)—agreements signed in Osnabrück and Münster—concluded the war and established a new balance of power that became a foundation for European relations for centuries to come. The purpose of this balance-of-power arrangement was to ensure that no single European state had the ability to dominate others, especially in the realm of international relations and their immediate security concerns.