The Framers worried most about unchecked power and understood that heads of state would war too much if left to their own devices.
In the clip above, I discuss the power to declare war with John Tabin of The American Spectator, and posit that when some conservatives argue that the president should have the power to unilaterally start a war, they're sneakily making a version of the "living, breathing Constitution" argument -- that is to say, they think that, unlike when Madison was writing up our founding document and a country had to send its navy across the ocean to mount a serious attack, we're faced with global threats with the potential to unfold too quickly to leave things to Congress. Put another way, times have changed, and the Constitution has to be malleable enough to change with them. (As you can see if you watch the clip, Tabin thinks I've got that wrong).
We go on to discuss the argument over the intentions of the Founders. And since I can't quote Madison from memory, I wanted to take this opportunity to quote one of his statements on the danger of war:
War is the parent of armies; from these proceed debts and taxes; and armies, and debts, and taxes are the known instruments for bringing the many under the domination of the few. In war, too, the discretionary power of the Executive is extended; its influence in dealing out offices, honors and emoluments is multiplied; and all the means of seducing the minds, are added to those of subduing the force, of the people. The same malignant aspect in republicanism may be traced in the inequality of fortunes, and the opportunities of fraud, growing out of a state of war, and in the degeneracy of manner and of morals, engendered in both.
No nation can preserve its freedom in the midst of continual warfare. War is in fact the true nurse of executive aggrandizement. In war, a physical force is to be created; and it is the executive will, which is to direct it. In war, the public treasuries are to be unlocked; and it is the executive hand which is to dispense them. In war, the honors and emoluments of office are to be multiplied; and it is the executive patronage under which they are to be enjoyed; and it is the executive brow they are to encircle. The strongest passions and most dangerous weaknesses of the human breast; ambition, avarice, vanity, the honorable or venal love of fame, are all in conspiracy against the desire and duty of peace.
I leave it to the reader to deduce whether he intended an executive who could start wars without Congressional assent.