when was the last time congress failed to approve military action when given the chance?

[MFrohike]

20. Debatable

The War Powers Act specifically disallows authorization via appropriations unless such authorization is explicitly allowed. Reno's DOJ argued against this, on the basic principle that Congress can't bind its own hands, but that reasoning is a bit weak. After all, Congress has the power to change federal law via statute. The failure to do so is indicative that it did not seek to indirectly amend the WPA through appropriations. I'll link the memo from the DOJ on this issue, so you can form your own opinion.

http://www.justice.gov/olc/final.htm