President Obama, on his first day in office, can make a number of changes that will mark a clean break with the Bush presidency. He can, and should, issue an executive order revoking any prior order that permits detainee mistreatment by any government agency. He should begin the process of closing Guantánamo, and he should submit to Congress a bill to end the use of military commissions, at least as presently constituted. Over the coming months he can pursue other reforms to restore respect for the Constitution, such as revising the Patriot Act, abolishing secret prisons and "extraordinary rendition," and ending practices, like signing statements, that seek to undo laws.

While these steps are all crucial, however, it is not enough merely to cease the abuses of power and apparent criminality that marked the highest levels of George W. Bush's administration. We cannot simply shrug off the constitutional and criminal misbehavior of the administration, treat it as an aberration and hope it won't happen again. The misbehavior was not an aberration--aspects of it, particularly the idea that the president is above the law, were present in Watergate and in the Iran/Contra scandal. To fully restore the rule of law and prevent any repetition of Bush's misconduct, the abuses of his administration must be directly confronted. As Indiana University law professor Dawn Johnsen--recently tapped by Obama to head his Office of Legal Counsel--wrote in Slate last March, "We must avoid any temptation simply to move on. We must instead be honest with ourselves and the world as we condemn our nation's past transgressions and reject Bush's corruption of our American ideals."

What we need to do is conceptually simple. We need to launch investigations to get at the central unanswered questions of Bush's abuse of power, commence criminal proceedings and undertake institutional, statutory and constitutional reforms. Perhaps all these things don't need to be done at once, but over time--not too much time--they must take place. Otherwise, we establish a doctrine of presidential impunity, which has no place in a country that cherishes the rule of law or considers itself a democracy. Bush's claim that the president enjoys virtually unlimited power as commander in chief at a time of war--which Vice President Dick Cheney defiantly reasserted just last month--brought us perilously close to military dictatorship.

As the former district attorney in Brooklyn, New York, I know the price society pays for a doctrine of impunity. Failure to prosecute trivializes and encourages the crimes. The same holds true of political abuses--failure to hold violators accountable condones the abuse and entrenches its acceptability, creating a climate in which it is likely to be repeated. The doctrine of impunity suggests, too, that there is a dual system of justice--one for the powerful and one for ordinary Americans. Because the concept of equal justice under the law is the foundation of democracy, impunity for high-level officials who abuse power and commit crimes erodes our democracy.

An impeachment proceeding against President Bush would have been the proper forum to expose the full scope of his abuses and to impose punishment. That obviously didn't happen, but investigations and prosecutions can still provide the vast civics lesson that an impeachment process would have given our nation.

There is another important reason for not "moving on." On January 20, Barack Obama will take an oath of office to uphold the Constitution, which requires the president to "take care that the laws be faithfully executed." Much as President Obama might like to avoid controversy arising from investigations and prosecutions of high-level Bush administration officials, he cannot let them get away with breaking the law without violating his oath. His obligation to pursue justice in these cases is all the more serious given his acknowledgment that waterboarding is torture--which is a federal crime--and the vice president's recent admission of his involvement in and approval of "enhanced" interrogation techniques.

Moreover, under the Geneva Conventions and the Convention Against Torture, our government is obliged to bring to justice those who have violated the conventions. Although Bush smugly ignored his constitutional duty to enforce treaty obligations and laws that punish detainee mistreatment, Obama cannot follow the same lawless path.

Investigations

The Iraq War, the torture and mistreatment of detainees, and the wiretapping and US Attorney scandals of the Bush administration merit new and full investigations that could be carried out singly or together and could be conducted by Congress or an outside commission.

The Iraq War has been a tragic mistake for America. More than 4,000 Americans have been killed, more than 30,000 wounded and the financial cost is expected to exceed $1 trillion. The cost to Iraqis in lives and destruction is much greater. This war was not just unnecessary; it was based on false claims. We were told we were justified in striking at Iraq because it posed the threat of weapons of mass destruction and because Saddam Hussein was in cahoots with Al Qaeda, which attacked us on 9/11. Those statements, as we now know, were blatantly untrue.

Despite several Congressional investigations, we never learned whether President Bush knew that the justifications for the war were untrue and whether he deliberately lied to drive the country into the war.

There are many indications that he did know. The Downing Street memo officially recorded a briefing given to British Prime Minister Tony Blair in July 2002 by his top intelligence official, who had just returned from meetings in Washington, eight months before the war began. According to the memo, Blair was told that the United States had already decided to remove Saddam and that the intelligence was going to be "fixed" around the policy. At the first National Security Council meeting in 2001, two years before the United States went to war, Treasury Secretary Paul O'Neill was astonished to find that the decision to invade Iraq had already been made--the question, he said, was not whether but when. Finally, the Senate Intelligence Committee not long ago found that most of the claims made for the need to go to war were not borne out by information in the possession of US intelligence agencies.

A 9/11 kind of commission or committees of Congress must commence an investigation to get at the truth of the presidential deceptions related to the war. Whether President Bush knowingly deceived us needs to be fully explored and exposed; if he did, he will at the very least have to carry that burden of disgrace permanently. Precisely because other presidents lied about warmaking--think of Lyndon Johnson and the Gulf of Tonkin resolution and Richard Nixon and the secret bombing of Cambodia--we know that future presidents will be tempted to do the same. Investigating and exposing the role of President Bush and his team in the deceptions causing the Iraq War may discourage future presidents from taking the same path.

Similarly, investigations need to be conducted into the torture and mistreatment of detainees held by the US government. The numerous investigations ordered by Defense Secretary Donald Rumsfeld in the wake of the Abu Ghraib disclosures obfuscated the question of responsibility at the highest level. They conveniently did not probe the role of the president; vice president; Justice Department officials, including the attorney general; or other cabinet secretaries. They also did not look at the actions of the Central Intelligence Agency.

The mistreatment was recently confirmed by the Senate Armed Services Committee, which in a bipartisan report found that it was initially traceable to President Bush's removal of Geneva Convention protections from members of Al Qaeda and the Taliban, and was a direct result of actions taken by Rumsfeld.

Full inquiries into responsibility for torture and mistreatment, however, need to be undertaken by a commission outside Congress, since some members of the House and Senate appear to have been apprised by the administration of the torture while it was going on and may have approved it. Members of Congress might be reluctant to sit in judgment of their colleagues, and in any case there would be a serious problem of appearances if they did.

Detainee mistreatment and torture have inflamed anti-American sentiment throughout the world, creating added risks to our soldiers and to Americans everywhere. Indeed, Abu Ghraib and Guantánamo have become rallying cries and recruitment tools for Al Qaeda. Revealing and documenting the whole story of detainee mistreatment, including the role of the CIA and the president and vice president, would go a long way toward changing public opinion about America at home and abroad.

The Bush administration's wiretapping program must also be reviewed. Although Congress has watered down the Foreign Intelligence Surveillance Act (FISA), it is important to understand the nature and scope of the intrusions into Americans' privacy under the program. As much information as possible, limited only by what is absolutely essential to protect national security, must be made public. For example, we do not yet know whether journalists, lawyers, political opponents and the like were subjected to wiretaps or other intrusions.

Investigations also need to be conducted into the president's role in the US Attorney scandal and the role of his aides Karl Rove and Harriet Miers and his Attorney General Alberto Gonzales. It appears that certain US Attorneys were removed from office solely because they failed to bring baseless prosecutions against Democrats in the 2006 election year, and that other US Attorneys were appointed to bring baseless prosecutions. The misuse of our criminal justice system for electoral ends is a grave abuse of power, and the facts behind the scandal must be uncovered.

In connection with the conviction of I. Lewis "Scooter" Libby for obstruction of justice, the administration classified the notes from the FBI's interview of Vice President Cheney. Those notes need to be declassified so the country can better understand the role he and the president played in the effort to "out" a clandestine CIA employee in retaliation for her husband's public claims that President Bush was taking the country to war under false pretexts. The FBI's notes of the president's interview should be made public as well.

Prosecutions

Some of the abuses of power in which President Bush and the top members of his team engaged may well constitute crimes.

Violation of FISA is a felony, and we know, through his own admissions, that Bush failed on at least forty occasions to obtain court approval for the wiretaps, despite the clear requirement of the statute that he do so. He even authorized wiretapping when the Justice Department refused to sign off on its legality. Subsequently the president worked with the FISA court to obtain authorization for the special program--a fact that strongly suggests court authorization could have been obtained much earlier, if not from the outset. Similarly, the president was able to persuade Congress to weaken the FISA protections a number of months ago. That shows that the president could have asked Congress to change the law from the outset (as he did with other parts of FISA). Instead, Bush took it upon himself brazenly and repeatedly to violate the law, authorizing wiretap after wiretap without seeking FISA court approval or revisions in the statute. No person, including a president, should be able to disobey the law this way.

Violation of the Anti-Torture Act is also a felony. This statute bars any US citizen from committing or attempting to commit torture abroad. Those who conspire with or aid and abet the torturers are penalized. The statute carries the death penalty when death results from the torture, and thus in those cases there is no statute of limitations on prosecution.

Undoubtedly Bush will claim that there should be no prosecution because the anti-torture statute cannot limit his powers as commander in chief. He may also claim that the mistreatment of detainees that was authorized did not constitute torture. Neither of these positions is a fatal bar to prosecution. The Supreme Court has ruled that a president's powers as commander in chief do not override statutes. And waterboarding, which the administration acknowledges took place (but on only three people), has long been viewed as torture.

If the investigations show that President Bush deliberately deceived the country about the Iraq War, then a determination should be made as to whether the lies are prosecutable under federal law. If so, a criminal proceeding on these grounds should be commenced.

The investigations and prosecutions should be conducted by one or more special prosecutors, since the Justice Department would have a serious conflict in prosecuting people who may claim to have followed its guidance or who were members of the department facilitating the torture.

The decision to prosecute Bush and lower-level officials who acted at the president's behest may seem too weighty to place in the hands of one person, no matter how seasoned, fair and reputable a prosecutor he or she may be, without establishing a full context for the prosecutions. After all, almost eight years of abuses have gone by with only a few whispers from the political establishment and the mainstream media about the need for criminal prosecutions. For that reason, designated Congressional committees or an outside commission should pursue inquiries into presidential abuses, particularly those that may also constitute crimes. These inquiries, which should not interfere with any criminal prosecutions, should aim to give the public an understanding of why the Bush Administration's actions are so grave and why the defense that a president may take the law into his own hands is unacceptable.

Reforms

The most pressing reform involves the War Crimes Act of 1996, which would be a more effective tool for prosecuting detainee mistreatment than the Anti-Torture Act. The president and other top officials were concerned about prosecution under that act, which makes cruel and inhuman treatment of detainees a federal crime. Like the anti-torture statute, it carries the death penalty when death results from the mistreatment, which means there is no statute of limitations. Administration officials might think they can avoid criminal liability under the Anti-Torture Act by claiming the mistreatment isn't torture (as in President Bush's oft-repeated claim that we "don't do torture"); but they know that they can't avoid liability under the War Crimes Act, because "harsh" interrogation techniques--waterboarding, stress positions, threatening dogs, exposure to temperature extremes--are all clearly cruel and inhuman. They can't get around the War Crimes Act with definitional tricks.

Following White House counsel Alberto Gonzales's advice in January 2002 about how to "reduce the likelihood of prosecution" under the War Crimes Act, President Bush opted out of the Geneva Conventions for members of Al Qaeda. Administration officials apparently thought this would enable them to avoid liability for mistreating those prisoners, because the War Crimes Act was intended to enforce the Geneva Conventions. But then the Supreme Court ruled in summer 2006 that the Geneva Conventions applied to Al Qaeda detainees, and the administration realized that something had to be done to prevent criminal liability under the act. So it quietly inserted a provision into the Military Commissions Act in October 2006 that made the War Crimes Act retroactively inoperative--meaning that past violations could not be prosecuted.

Retroactively nullifying the War Crimes Act was one of the Bush administration's most cynical acts with respect to the rule of law. In essence, it issued a blanket pardon to anyone who had violated the War Crimes Act, including the president and vice president. There was no examination of the facts of any particular case. The violations, whether egregious or minor, were swept under the rug. No one was ever to be called to account. The crimes were made to disappear--poof. This maneuver may be the worst embodiment of the doctrine of impunity for high-level government officials in our history. It cannot be allowed to stand.

Fortunately, the retroactive nullification can be undone and the original law resurrected. Once the War Crimes Act is restored, a special prosecutor should determine whether and how to prosecute under the act. But even if no prosecutions are brought against President Bush and his team, by restoring the original law, we put an end to the horrific situation in which a criminal statute is decriminalized after crimes are committed to protect people in the highest offices.

A second reform is limiting the president's pardon power. This must be done by constitutional amendment. One of the ways a president can execute illegal schemes is to assure subordinates that they will not face criminal liability. To prevent this kind of high-level conspiracy, the amendment should prohibit a president from pardoning anyone he or she appointed to office, or the vice president. Prohibitions against self-pardoning or pardoning in return for a bribe should also be clearly spelled out in the amendment.

A third reform would re-enact legislation creating a special prosecutor for crimes committed by high-level government officials. The original law was allowed to expire after the sorry excesses of special prosecutor Kenneth Starr. A new statute, devised to prevent such excesses, would permit prosecution of officials when the Justice Department cannot or will not investigate--as happened repeatedly during the Bush era. (The appointment of Patrick Fitzgerald in the Valerie Plame leak case was fortuitous; the attorney general was incapacitated, so the power to appoint a special prosecutor fell to a nonpolitical professional prosecutor.) The problem extends beyond the Bush administration: no attorney general can be expected to investigate the president who appointed him or her.

Sooner or later, America will confront the abuses of the Bush presidency head-on. The only question is whether we will wait for years--as Chile did with respect to bringing Gen. Augusto Pinochet to justice--or do it now, sending a clear signal that our country is back on track and firmly embraces the rule of law.