Professor Marjorie Cohn is a professor at Thomas Jefferson School of Law (where she teaches criminal law and procedure, evidence, and international human rights law) and .the immediate past president of the US National Lawyers Guild (see: http://www.marjoriecohn.com/ and http://www.nlg.org/ ).
Professor Marjorie Cohn on the illegality of the Afghanistan-Pakistan war (2009): “Although the U.S. invasion of Afghanistan was as illegal as the invasion of Iraq, many Americans saw it as a justifiable response to the attacks of September 11, 2001. The cover of Time magazine called it "The Right War." Obama campaigned on ending the Iraq war but escalating the war in Afghanistan. But a majority of Americans now oppose that war as well.
The UN Charter provides that all member states must settle their international disputes by peaceful means, and no nation can use military force except in self-defense or when authorized by the Security Council. After the 9/11 attacks, the council passed two resolutions, neither of which authorized the use of military force in Afghanistan. “Operation Enduring Freedom” was not legitimate self-defense under the charter because the 9/11 attacks were crimes against humanity, not “armed attacks” by another country. Afghanistan did not attack the United States. In fact, 15 of the 19 hijackers hailed from Saudi Arabia. Furthermore, there was not an imminent threat of an armed attack on the United States after 9/11, or President Bush would not have waited three weeks before initiating his October 2001 bombing campaign. The necessity for self-defense must be “instant, overwhelming, leaving no choice of means, and no moment for deliberation.” This classic principle of self-defense in international law has been affirmed by the Nuremberg Tribunal and the UN General Assembly. Bush's justification for attacking Afghanistan was that it was harboring Osama bin Laden and training terrorists, even though bin Laden did not claim responsibility for the 9/11 attacks until 2004. After Bush demanded that the Taliban turn over bin Laden to the United States, the Taliban’s ambassador to Pakistan said his government wanted proof that bin Laden was involved in the 9/11 attacks before deciding whether to extradite him, according to the Washington Post. That proof was not forthcoming, the Taliban did not deliver bin Laden, and Bush began bombing Afghanistan. Bush’s rationale for attacking Afghanistan was spurious. Iranians could have made the same argument to attack the United States after they overthrew the vicious Shah Reza Pahlavi in 1979 and the U.S. gave him safe haven. If the new Iranian government had demanded that the U.S. turn over the Shah and we refused, would it have been lawful for Iran to invade the United States? Of course not. When he announced his troop “surge” in Afghanistan, Obama invoked the 9/11 attacks. By continuing and escalating Bush’s war in Afghanistan, Obama, too, is violating the UN Charter. In his speech accepting the Nobel Peace Prize, Obama declared that he has the "right" to wage wars "unilaterally.” The unilateral use of military force, however, is illegal unless undertaken in self-defense.” [1].
[1]. Marjorie Cohn, “Obama’s Af-Pak war is illegal”, MWC News, 21 December 2009: http://mwcnews.net/content/view/35138/42/ .