If certain Democrats and sympathetic Republicans ever were to succeed in passing legislation actually tying the hands of President Bush with respect to the operational conduct of the Iraq War that impinged on his powers as Commander-in-Chief, the Supreme Court might well strike down such legislation (and everyone knows who holds sway on the current high court as a result of two key appointments earlier in the President's term of office).
That said, and I am by no means a constitutional lawyer, firm and unambiguous legislation aimed at compelling the President, before initiating any offensive (vice defensive) military action against Iran, to seek formal Congressional approval could be the reverse: reducing the President's ability to overstep his powers as Commander-in-Chief. This is an area very much worth debating since what he and past presidents have done militarily without declarations of war since 1950 falls into a huge gray area that has not been properly examined, despite the more than 30 years that have elapsed since the end of the Vietnam War. I might also have added Korea and the 1991 Gulf War in this context, but both were conducted as part of a United Nations Security Council-sanctioned execution of a UN Chapter VII mandate.
Since December 1941, U.S. Presidents have engaged in two major conflicts of choice (Vietnam and the 2003 Iraq War) without formal declarations of war or even any explicit Chapter VII authorization on the part of the UN Security Council, actions largely unknown in the American pre-World War II experience. Ironically, although Korea ended in a highly unpopular stalemate, the Vietnam conflict and the current Iraq War have been the only truly disastrous major military actions since the Second World War.
Perhaps, with respect to risk, the ultimate potential exercise in Congressionally unregulated Presidential power as Commander-in-Chief (in terms of consequences for this nation and the world had there been resort to military force) was the 1962 Cuban Missile Crisis. Had President Kennedy exercised military options beyond reconnaissance and blockade, and Premier Khruschev responded in kind, "disastrous" might not have been anywhere near an appropriate description for the results of any resultant escalation .
In this discussion, I have not, of course, mentioned lesser cases such as the U.S. invasions of the Dominican Republic (1965), Grenada (1983) or Panama (1989) because in the decades prior to WWII the U.S. already had engaged in a number of highly controversial "interventions" in Latin America, and in that earlier era also without any real warmaking authority--not even the OAS support that accompanied some U.S. actions in the post-WWII era.
I am fully aware of some of the frequently-stated and sometimes awkward aspects (legal and otherwise) related to formal declarations of war, but perhaps even these considerations might give a President pause before asking for a declaration of war, as well as for the Congress to ponder before voting in favor or against one.
For those not yet aware, under the aegis of the University of Virginia's Miller Center of Public Affairs, a National War Powers Commission has been established to explore these very issues from the perspective of both the Presidency and the Congress, led by none other than former Secretary of State James Baker (along with former Secretary Warren Christopher), with 10 other commission members, among them former Representative Lee Hamilton. This is reminiscent of the largely-ignored Iraq Study Group findings of last December, but let us hope sage advice or recommendations emanating from this new quarter will not meet the same fate as the bulk of the ISG's 79 recommendations.
Middle East Institute
Middle East Policy Council