It does so by entrusting exclusive authority for initiating war in Congress, the branch of government whose powers are diminished by military conflict.
War concentrates great powers in the presidency and wrenches the Constitution's separation of powers and checks and balances. It crowns the president with secrecy, contracts, appointments, vast powers of surveillance and detention, and the authority to kill. Congress and the Supreme Court are marginalized like extras in a cinematic extravaganza. James Madison, father of the Constitution, elaborated:
"Of all the enemies to public liberty war is, perhaps, the most to be dreaded, because it comprises and develops the germ of every other.