Has Congress Amended An AUMF In The Past?

Earlier today, Russ Feingold began holding hearings on whether Congress had the authority to rescind or modify an authorization for the use of military force (AUMF), once approved and implemented by the executive. This weekend, I argued that Congress could not simply rescind an AUMF without the executive declaring an end to hostilities, once given command of the war. Feingold plans to use the hearings to demonstrate that Congress can indeed overrule the executive, withdraw their AUMF, and force an end to a deployment.
Does Congress have any precedent for such an action? This was the subject of a friendly set of e-mails between myself and Glenn Greenwald after he posted examples of Republican Senators demanding an end to our deployment in Somalia after the debacle of Mogadishu. These include Jesse Helms, Strom Thurmond, Phil Gramm, and John McCain, who made the case for Senatorial action:

Dates certain, Mr. President, are not the criteria here. What is the criteria and what should be the criteria is our immediate, orderly withdrawal from Somalia. And if we do not do that and other Americans die, other Americans are wounded, other Americans are captured because we stay too long–longer than necessary–then I would say that the responsibilities for that lie with the Congress of the United States who did not exercise their authority under the Constitution of the United States and mandate that they be brought home quickly and safely as possible.

I challenged Glenn about the use of Somalia as an example, as I did not believe that Congress had ever passed an AUMF for action against Somalian warlords — which then created the opening for Congress to demand the withdrawal of the troops. In the case of Iraq, Congress granted the executive the AUMF to conduct the war and that made this a significantly different situation; the two were not analogous. I could not research the question myself at the time (I was reading Glenn’s argument on a break from work), but Glenn offered to check it out and get back to me.
He e-mailed me later this afternoon, and provided this document as background on the question. It summarizes Congressional involvement in military action over the last twenty-five years, prepared by the Congressional Research Service of the Library of Congress. The section on Somalia seems to indicate that some sort of AUMF did indeed get issued — and was amended several times to set a deadline for the removal of American troops from Somalia (page 10):

S.J.Res. 45
Joint resolution authorizing the use of United States Armed Forces in Somalia pursuant to United Nations Security Council Resolution 794 providing for a secure environment to deliver relief supplies into Somalia. February 4, 1993: Measure passed Senate (voice vote). May 25, 1993: Measure passed House, 243-179 (roll call vote #183). The House reported version authorized U.S. troops under the War Powers Resolution, but terminated such authorization at the earlier of (1) end of one year from date of enactment of the act unless extended by Congress; or (2) expiration of the United Nations-led force in Somalia.

It’s of interest to note that the outgoing Bush administration did not go to Congress to authorize the initial deployment, instead choosing to use the UNSC resolution to initiate the mission. Starting in October 1993, though, the mood of Congress changed. Both Democrats and Republicans submitted amendments to the original AUMF to end the authorization on specific dates. The dates ranged from January 31, 1994 to their eventual full withdrawal in March 1995. Strom Thurmond had to beat back a McCain amendment at that time to prohibit all expenditures on the military mission in Somalia except that necessary to bring the troops home. The Byrd amendment passed, which essentially did the same thing but extended the deadline to March 31, 2004, unless the mission was reauthorized by Congress.
This demonstrates more that Congress can use the power of the purse to end a military deployment rather than to withdraw an AUMF, once given. Also, it is unclear whether the AUMF for Somalia actually authorized offensive military action; that mission expansion certainly inspired some of the anger seen in Glenn’s post from Senate Republicans at that time. The precedent does exist for Congress to set limits on deployments, though — that much is clear from the Congressional history of our Somalian mission.
If Congress has the legal authority to make such a move, it still remains an open question whether such action would be wise politically. It puts responsibility on Congress, mostly the Democrats, if a precipitate withdrawal leads to a collapse in Iraq, systematic genocides, and the rise of a terrorist state that would require another American invasion to destroy.
Addendum: The troops don’t appear to favorite it much, as this YouTube demonstrates (via McQ at QandO):
They’re obviously not buying the “support the troops, oppose the mission” meme.
UPDATE: Deleted the YouTube video, due to some technical glitch; it apparently prevented the entire page from loading. Hat tip to Tom Holsinger in the comments.