Does the War Powers Act effectively restrict the ability of the US president to wage war?

The War Powers Act on its own has not been a significant
restriction on the ability of the US president to wage war.  It is one tool that
Congress can use to pressure a president, but it has never, on its own, been used to
prevent a president from acting as he wished.

A major
reason for this is that the War Powers Act has never been formally declared
constitutional.  No president has ever acknowledged that the act actually has any
force.  This keeps the act from being a very effective restriction on the president's
ability to wage war.

However, this is not to say that the
act is meaningless.  It can be used as an effective rhetorical tool against the
president.  It can force him (or someday her) to justify his actions to the American
people.  It is public opinion that ultimately ends up being the most effective check on
the president's ability to wage an undeclared war.