On Wednesday, the White House provided Congress with a report on US operations in Libya. This report claims that the US military's ongoing involvement in Libya does not amount to "hostilities" and, as such, does not require the approval of Congress. In this assertion, the Obama administration is engaging in legal spin of the worst kind.
While the president is the commander-in-chief of the US military, since the passage of the War Powers Resolution in 1973, Congress has required that the president seek congressional approval for combat operations continuing after a period of 60 days. This resolution expanded the implied authority of Congress that stems from the constitutional power of Congress to declare war. While the US supreme court has not visited the constitutionality of the War Powers Resolution, the resolution's precedence has motivated all presidents since Nixon to seek approval (if sometimes indirectly) for relevant US military deployments abroad. This included President George W Bush with regard to both Iraq and Afghanistan.
In the case of Iraq, while a senator, Obama was inclined to a highly assertive consideration of the reach of congressional war authority. In this context, that the Obama administration is now arguing US military involvement in Libya does not require authorisation from Congress is patently absurd. In terms of both material support and strategy, the US is unquestionably engaged in hostilities against the Libyan regime.