That phrase comes from Kant, but it is also the title of an excellent book that I am reading at the moment by Margaret Jacob (U of Penn Press, 2006). Jacob's book is about the rise of cosmopolitanism in Early Modern Europe. It is, in short, about the rise of European Liberalism.
This last point I want to stress because too often in the popular media the teachings of the Austrian school are identified with conservative politics when in fact the great Austrian economists, such as Menger, Mises and Hayek were in fact European Liberals. Radical liberals that opposed intolerance, militarism, and arbitrary state authority. Yes they were economic liberals, but their views on economic policy were part of a larger world view that followed consistently from an embracing of the cosmopolitanism that Jacob writes about.
For anyone who doubts this, read Mises's Liberalism. As he says on p. 56, "Liberalism demands toleration as a matter of principle, not from opportunism." Only toleration, he continues, "can create and preserve the condition of social peace without which humanity must relapse into barbarism and penury of centuries long past."
On colonialism, Mises wrote: "No chapter of history is steeped further in blood than the history of colonialism. Blood was shed uselessly and senselessly. Flourishing lands were laid waste; whole peoples destroyed and exterminated. All this can in no way be extenuated or justified." (see p. 125)
Every sort of national chauvinism is to be rejected, and instead the free mobility of people and goods is to be pursued. We are to be citizens of the world. Cosmopolitanism, toleration, trade are the hallmarks of liberalism. That is what Ludwig von Mises stood for in his politics.