"would be extraordinary for the Court to permit one side to unilaterally amend an agreement already jointly reached and signed. Moreover, early in the Court's review of the joint motion, but after the new administration was in office in Washington, the Government affirmed its commitment to this draft and urged the Court to sign it. The Defendants, for their part, continue to urge entry of the proposed decree, consistent with the earlier joint submission. As between the parties, this case is settled."