Practice confirms that the president, under his
commander-in-chief and other executive powers, has very broad
discretion to use U.S. military force in the absence of congressional
authorization. Presidents have done this, in military actions large and
small, over 100 times, since the beginning of the republic. The largest
and most consequential unauthorized military action is the Korean War
launched by President Truman in 1950. Another big conflict without
congressional authorization—and, indeed, in the face of an overt
congressional vote that declined to provide such authorization—was
President Clinton's Kosovo intervention in 1999. Some less significant
unilateral uses of military force in the past 30 years include Haiti
(2004), Bosnia (1995), Haiti (1994), Somalia (1992), Panama (1989),
Libya (1986), Lebanon (1982), and Iran (1980). The executive branch has
issued public legal opinions explaining the constitutional basis for
most of these actions.
Critics claim that a pattern of consistently violating the Constitution
cannot remedy the illegality of these actions. But that is not the
right way to view this pattern. An important principle of
constitutional law—especially when the allocation of power between the
branches is at issue—is that constitutional meaning gets liquidated by
constitutional practice. As Chief Justice William H. Rehnquist
explained in his opinion in Dames and Moore vs. Regan
http://www.law.cornell.edu/supct/html/historics/USSC_CR_0453_0654_ZO.html:
" A systematic, unbroken, executive practice, long pursued to the
knowledge of the Congress and never before questioned … may be treated
as a gloss on 'Executive Power' vested in the President by § 1 of Art.
II. Past practice does not, by itself, create power, but long-continued
practice, known to and acquiesced in by Congress, would raise a
presumption that the [action] had been [taken] in pursuance of its
consent."
Congress has known about this pattern of presidential unilateralism for
some time and done little in response. It has never impeached a
president for using force in this way. It has continued to finance an
enormous standing military force in the face of this practice. And it
has done practically nothing by statute to push back on the president's
power to initiate military action with that standing military force.
Not even the famous War Powers Resolution of 1973 does much to address
the unauthorized initiation of force by a president. It requires the
president to submit a report to Congress within 48 hours whenever armed
forces are introduced "into hostilities or into situations where
imminent involvement in hostilities is clearly indicated by the
circumstances." After the president reports the introduction of forces
abroad, the resolution requires him to withdraw those forces within 60
days (or 90 days, based on military necessity) unless Congress has
authorized continued operations.
