In 2006 the law of war experienced two major shock waves. The first was the decision of the Supreme Court in Hamdan, which represented the first major defeat of the President’s plan, based on an executive order of November 2001, to use military tribunals against suspected international terrorists. The majority of the Court held the procedures used in the military tribunal against Hamdan violated common article three of the Geneva Conventions. A plurality of four, with the opinion written by Justice Stevens, based their decision as well on a far-reaching interpretation of the substantive law of war. They held that conspiracy to commit terrorist acts did not fall under the customary international law of war. Congress responded by enacting the Military Commissions Act of 2006. The President signed the bill on October 17. The interpretation of Hamdan and the precedents on which it is based will shape future litigation about the constitutionality of the various provisions of this legislation.