Feel free to find five of these reasons crazy. Any one of them should be sufficient alone.
- War is illegal. While all wars are illegal under the Kellogg-Briand Pact, most people ignore that fact. Yet, many fewer ignore the fact that virtually all wars are illegal under the UN Charter. President Biden defended his recent missiles into Syria with a ridiculous claim of self-defense, explicitly because there is a self-defense loophole in the UN Charter. The U.S. sought UN authorization for the 2003 attack on Iraq (but didn't get it) not as a courtesy to the dispensable nations of the world, but because that's the legal requirement, even if ignoring the existence of the Kellogg-Briand Pact (KBP). There is no way for Congress to word an Authorization for the Use of Military Force (AUMF) to make the crime of war into something legal. There is no way for Congress to finesse it by claiming that some level of force isn't actually a "war." The UN Charter bans force and even the threat of force, and requires the use of only peaceful means as does the KBP. Congress has no special dispensation to commit crimes.
- Stipulating for the sake of argument that war is legal, an AUMF would still be illegal. The U.S. Constitution gives Congress the exclusive power to declare war, and no power to authorize an executive to declare war. Stipulating for the sake of argument that the War Powers Resolution is Constitutional, its requirement that Congress specifically authorize any war or hostilities cannot be met by declaring that a general authorization of the executive to authorize whatever wars or hostilities he or she sees fit simply is a specific authorization. It isn't.
- You do not end wars by authorizing wars or by authorizing someone else to authorize wars. The 2001 AUMF stated: "That the President is authorized to use all necessary and appropriate force against those nations, organizations, or persons he determines planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001,or harbored such organizations or persons, in order to prevent any future acts of international terrorism against the United States by such nations, organizations or persons." The 2002 AUMF said: "The President is authorized to use the Armed Forces of the United States as he determines to be necessary and appropriate in order to (1) defend the national security of the United States against the continuing threat posed by Iraq; and (2) enforce all relevant United Nations Security Council resolutions regarding Iraq." These laws are nonsense, not just because they are unconstitutional (see #2 above) but also because the second one's dishonest whereas clauses connecting Iraq to 9-11 render it unnecessary under the first one. Yet, that second one was necessary politically in the United States. A new AUMF was also necessary for Syria 2013 and Iran 2015, which is why those wars did not happen on an Iraqlike scale. That another declaration or AUMF was not necessary for numerous other wars, including the war on Libya, including the smaller scale and proxy war on Syria, is a political fact more than a legal one. We are completely capable of making it necessary for Biden to obtain a new pseudo-declaration of war for any new war, and of denying it to him. But handing him a new AUMF now and expecting him to put all the missiles away and behave like a grownup would be tying one hand behind our backs as advocates for peace.
- If Congress cannot be compelled to repeal existing AUMFs without creating a new one, we're better off keeping the old ones. The old ones have added a layer of legalisticishness to dozens of wars and military actions, but not actually been relied upon by Bush or Obama or Trump, each of whom has argued, absurdly, that his actions were (a) in compliance with the UN Charter, (b) in compliance with the War Powers Resolution, and (c) authorized by nonexistent presidential war powers imagined into the U.S. Constitution. At some point Congress's excuses for passing the buck fade into ridiculousness. There is still on the books from 1957 an authorization to combat international communism in the Middle East, but nobody mentions it. I'd love to get rid of all such relics, and for that matter half the Constitution, but if the Geneva Conventions and the Kellogg-Briand Pact can be memory-holed, so can these outrageous Cheney-droppings. On the other hand, if you create a new one, it will be used, and it will be abused beyond whatever it literally states.
- Anyone who'd seen the damage done by recent wars would not authorize another goddamned thing. Since 2001, the United States has been systematically destroying a region of the globe, bombing Afghanistan, Iraq, Pakistan, Libya, Somalia, Yemen, and Syria, not to mention the Philippines and other countries scattered around the world. The United States has "special forces" operating in dozens of countries. The people killed by the post-9-11 wars is likely around 6 million. Many times that have been injured, many times that indirectly killed or injured, many times that made homeless, and many times that traumatized. A huge percentage of the victims have been little children. Terrorist organizations and refugee crises have been generated at an amazing pace. This death and destruction is a drop in the bucket compared to the lost opportunities to save people from starvation and illness and climate-disasters. The financial cost of over $1 trillion each and every year for U.S. militarism has been and is a trade-off. It could have done and could do a world of good.
- What's needed is something else entirely. What's actually needed is to compel an end to each war, and to weapons sales, and to bases. The U.S. Congress actually acted to (redundantly but apparently necessarily) forbid war on Yemen and on Iran when Trump was in the White House. Both actions were vetoed. Both vetoes were not overridden. Now Biden has committed to sort of kind of partially ending U.S. participation (except in certain ways) in the war on Yemen, and Congress has gone mute. What's actually needed is for Congress to forbid any participation in the war on Yemen and make Biden sign it, and then the same on Afghanistan, and then the same on Somalia, etc., or do several at once, but do them, and make Biden sign or veto them. What's needed is for Congress to forbid murdering people around the globe with missiles, whether or not from drones. What's needed is for Congress to move the money from military spending to human and environmental crises. What's needed is for Congress to end U.S. weapons sales currently going to 48 of the 50 most oppressive governments on earth. What's needed is for Congress to close the foreign bases. What's needed is for Congress to end deadly and illegal sanctions on populations around the world.
Otherwise, what was the point of getting a new Congress and president? To provide less pandemic aid than Trump did? To tease suffering people with a minimum wage law and do a little dance about it? If Congress cannot forbid even the wars it pretended to want to forbid when it had vetoes it could count on, what is the purpose of Congress?