The means of defence against foreign danger have been always the instruments of tyranny at home.

James Madison in a Speech, Constitutional Convention (1787-06-29), from Max Farrand's Records of the Federal Convention of 1787, vol. I [1] (1911), p. 465

In time of actual war, great discretionary powers are constantly given to the Executive Magistrate. Constant apprehension of War, has the same tendency to render the head too large for the body. A standing military force, with an overgrown Executive will not long be safe companions to liberty. The means of defence against foreign danger have been always the instruments of tyranny at home. Among the Romans it was a standing maxim to excite a war, whenever a revolt was apprehended. Throughout all Europe, the armies kept up under the pretext of defending, have enslaved the people.