In the debate between “Pacificius” (Hamilton) and “Helvidius” (Madison) on the proper powers of the executive (President) and legislative (Congress) branches of government Madison argued that the traditional “monarchical” powers of declaring and waging war had been separated in the American republic:
A declaration that there shall be war, is not an execution of laws: it does not suppose preexisting laws to be executed: it is not in any respect, an act merely executive. It is, on the contrary, one of the most deliberative acts that can be performed; and when performed, has the effect of repealing all the laws operating in a state of peace, so far as they are inconsistent with a state of war: and of enacting as a rule for the executive, a new code adapted to the relation between the society and its foreign enemy….
Those who are to conduct a war cannot in the nature of things, be proper or safe judges, whether a war ought to be commenced, continued, or concluded. They are barred from the latter functions by a great principle in free government, analogous to that which separates the sword from the purse, or the power of executing from the power of enacting laws.
About this Quotation:
When war broke out between France and the monarchies of Europe in April 1792 the new American Republic faced a difficult choice between maintaining its alliance with France which had been of so much help during the American Revolution, and declaring its neutrality. A spirited debate ensued between “Pacificus” (Alexander Hamilton), who believed the President should be able to make or break treaties and declare and wage wars (much like traditional monarchs) without Congressional authorization, and “Helvidius” (James Madison), who argued that precisely because making treaties and declaring wars were “monarchical powers” they had been separated in the American republican constitution of 1787. Madison argued that a declaration of war meant in practice “repealing all the laws operating in a state of peace” and hence grossly overstepped the bounds of the “executive” function, namely “executing” the laws passed by Congress. Furthermore, he raised the “quis custodiet ipsos custodes” argument, i.e. “who will guard us from the guardians”, if those who will wage the war also have the power to decide if and when to declare war.