Specifically, he noted that respect for the right of self-determination required extant states to allow the separation of new polities seeking secession. He writes:

The right of self-determination in regard to the question of membership in a state thus means: whenever the inhabitants of a particular territory, whether it be a single village, a whole district, or a series of adjacent districts, make it known, by a freely conducted plebiscite, that they no longer wish to remain united to the state to which they belong at the time, but wish either to form an independent state or to attach themselves to some other state, their wishes are to be respected and complied with.

Where does Mises get this idea of self-determination? He did not invent the idea, of course, but at the time was likely drawing upon currents of thought alive and well in Europe in the late nineteenth and early twentieth centuries.

Origins in the American Revolution

The concept of self-determination—albeit not the phrase—was already well-known as the driving force behind the American revolutionaries when the colonies seceded from the British Empire in the 1770s. Historian David Armitage describes the United States' war for independence as essentially the practical and political starting point for modern ideas of self-determination. While the philosophical roots of self-determination are often attributed to Immanuel Kant, the prototype for a real-life secession movement was found primarily in the American war for independence. Armitage writes: "The notion that "one People" might find it "necessary" to dissolve its links with a larger polity—that is, that it might legitimately attempt to secede . . . was almost entirely unprecedented and barely accepted at the time of the American Revolution."

The success of the United States in asserting a right of self-determination provoked similar movements in Europe and Latin America in the decades following American independence. For instance, Armitage notes that "language for self-determination" found in the Declaration of Independence would show up repeatedly Latin American, European, and Asian movements seeking political independence.