The National Security Council convened again that afternoon, and the president went around the table, asking each of us for our thoughts on the road ahead. I spoke last. I stressed that preventing the next attack had to be our top priority. We had to make sure we were leaving no stone unturned in that effort. Improvements in visa procedures, border control, and immigration security were critical, and we had to think more broadly. We had to do everything we could to keep those who would harm us from arming themselves with weapons of mass destruction.

We also had to realize that defending the homeland would require going on the offense. Relying only on defense was insufficient. The terrorists had to break through our defenses only one time to have devastating consequences. We needed to go after them where they lived in order to prevent attacks before they were launched.

Although we had discussed Iraq earlier in the day, I also took time now to say that Afghanistan, where the 9/11 terrorists had trained and plotted, should be first. I believed it was important to deal with the threat Iraq posed, but not until we had an effective plan for taking down the Taliban and denying al Qaeda a safe haven in Afghanistan.

* * *

Mr. Cheney describes the path that led to “enhanced interrogation” of terror detainees and the results of the controversial program:

In March 2002, Pakistani forces raided an al Qaeda safe house in Faisalabad, Pakistan, and captured a terrorist named Abu Zubaydah. A lieutenant of Osama bin Laden, Zubaydah was the highest-ranking al Qaeda member we had captured to date….

Although defiant, Zubaydah provided useful information very early on, disclosing, for example, that the mastermind behind 9/11 had been Khalid Sheikh Mohammed, or KSM. He also provided KSM’s code name, Muktar. But then he stopped answering questions, and the CIA, convinced he had information that could potentially save thousands of lives, approached the Justice Department and the White House about what they might do to go further in interrogating him and other high-value detainees. The CIA developed a list of enhanced interrogation techniques that were based on the Survival, Evasion, Resistance, and Escape Program used to prepare our military men and women in case they should be captured, detained, or interrogated. Before using the techniques on any terrorists, the CIA wanted the Justice Department to review them and determine that they complied with the law, including international treaty obligations such as the United Nations Convention Against Torture. Out of that review process, which took several months, came legal opinions advising that the techniques were lawful. The program was approved by the president and the National Security Council.

Mr. Cheney and President George W. Bush share a lighter moment in the Oval Office in 2002

The techniques worked. Abu Zubaydah gave up information about Ramzi bin al Shibh, who had assisted the 9/11 hijackers, and on the one-year anniversary of the 9/11 attacks, bin al Shibh was captured after a shootout in Pakistan. At the time of his apprehension, he was plotting to use commercial airliners in suicide attacks on Heathrow Airport and other structures in London.

Information from Abu Zubaydah and bin al Shibh led in turn to the capture of KSM, who after being questioned with enhanced techniques became a fount of information. A CIA report, declassified at my request, notes that KSM was the “preeminent source on al-Qa’ida.” According to the 2004 report, KSM had become key in the U.S. government’s understanding of al Qaeda plots and personalities:

“Debriefings since his detention have yielded . . . reports that have shed light on the plots, capabilities, the identity and location of al Qa’ida operatives and affiliated terrorist organizations and networks. He has provided information on al Qa’ida’s strategic doctrine, probable targets, the impact of striking each target set, and likely methods of attacks inside the United States.”

In one instance KSM provided information that led us to a terrorist cell in Karachi, Pakistan. The members of the cell were being groomed by a terrorist named Hambali, al Qaeda’s point person for Southeast Asia, for operations against the United States, probably to fly a hijacked plane into the tallest building on the West Coast.

Despite the invaluable intelligence we were obtaining through the program of enhanced interrogation, in 2005 there was a move on Capitol Hill, led by Senators John McCain and Lindsey Graham, to end it and require that all U.S. government interrogations be conducted under the rules of the U.S. Army Field Manual….

In an effort to reach an agreement with Senator McCain and explain to him how damaging his proposed amendment would be, CIA Director Porter Goss and I met with him in a secure conference room at the Capitol and tried to brief him about the program and the critical intelligence we had gained. But John didn’t want to hear what we had to say. We had hardly started when he lost his temper and stormed out of the meeting.

* * *

The decision to invade Iraq was made after years of warnings from intelligence agencies across several U.S. administrations, Mr. Cheney writes:

In 1998 Saddam Hussein insisted that international weapons inspectors stop work and leave Iraq. In response, Congress passed and President Clinton signed into law the Iraq Liberation Act, making regime change in Iraq the policy of the United States government and approving nearly $100 million to fund Iraqi opposition groups working for Saddam’s ouster.

That December, President Clinton launched Operation Desert Fox, a four-day air strike campaign meant to diminish Saddam’s weapons capabilities. “If Saddam defies the world and we fail to respond, we will face a far greater threat in the future,” President Clinton said. “Mark my words, he will develop weapons of mass destruction. He will deploy them, and he will use them.”

There was bipartisan support for the operation. Among the Democrats who spoke out was Rep. Nancy Pelosi, then a member of the House Intelligence Committee. “Saddam Hussein has been engaged in the development of weapons of mass destruction technology which is a threat to countries in the region,” she said, “and he has made a mockery of the weapons inspections process.” A number of senators, including Democrats John Kerry, Carl Levin and Tom Daschle, wrote to President Clinton urging that he “take necessary actions (including, if appropriate, air and missile strikes on suspect Iraqi sites) to respond effectively to the threat posed by Iraq’s refusal to end its weapons of mass destruction programs.” Sen. Joe Biden, writing in The Washington Post two months before the strikes, noted the limitation of any policy that left Saddam in power. “Ultimately, as long as Saddam Hussein is at the helm, no inspectors can guarantee that they have rooted out the entirety of Saddam Hussein’s weapons program,” he wrote, and he observed that “the only way to remove Saddam is a massive military effort, led by the United States.”

… One of the first intelligence reports that George Bush and I received in late 2000 before we were sworn in was a far-ranging assessment of Iraq’s activities concerning weapons of mass destruction. Although the report itself remains classified, the title does not. It was called “Iraq: Steadily Pursuing WMD Capabilities.” As there had been in the preceding decade, there would be over the next 27 months a steady drumbeat of intelligence warnings about the threat posed by Saddam.

There were also by this time 16 United Nations Security Council resolutions aimed at mitigating the danger arising from Iraq. Saddam repeatedly violated them, ignoring requirements related to weapons of mass destruction as well as those that had to do with terrorism. Resolution 687, passed in 1991, had declared that Iraq must not commit or support terrorism, or allow terrorist organizations to operate in Iraq. But in 1993 the Iraqi Intelligence Service (IIS) attempted to assassinate former President George H. W. Bush, and throughout the 1990s, the IIS participated in terrorist attacks. Saddam provided safe haven to Abdul Rahman Yasin, the Iraqi bomb maker who supplied the bomb for the first attack on the World Trade Center, in 1993. He also provided sanctuary to Abu Abbas, the Palestinian terrorist who led the 1985 hijacking of the cruise ship Achille Lauro and the killing of an American passenger; and to Abu Nidal, who had killed a number of civilians in attacks on El Al ticket counters at airports in Rome and Vienna.

In the wake of 9/11, after the United States had gone into Afghanistan in Operation Enduring Freedom, CIA Director George Tenet told the Senate Select Committee on Intelligence, “We have solid evidence of the presence in Iraq of al Qaeda members, including some that have been in Baghdad.”

… In Senate testimony in 2003, Director Tenet also noted that Iraq was providing safe haven to Abu Musab al Zarqawi, a Jordanian-born terrorist who had trained in Afghanistan and become a key al Qaeda lieutenant. He had arrived in Iraq in 2002, spent time in Baghdad, and then supervised camps in northern Iraq that provided a safe haven for as many as 200 al Qaeda fighters escaping Afghanistan. At one of those camps, called Khurmal, Zarqawi’s men tested poisons and plotted attacks to use them in Europe. From his base in Iraq, Zarqawi also directed the October 2002 killing of Laurence Foley, a U.S. Agency for International Development officer, in Jordan.

For a period extending back to the first Gulf War, the U.S. intelligence community had been providing detailed assessments concerning Saddam Hussein’s efforts to develop nuclear weapons, carry on biological and chemical weapons programs, and support terror. The National Intelligence Estimate that we received in 2002 was a continuation of earlier evaluations, and sobering as its judgments were, what the president and I read in our daily briefings was even “more assertive,” as Director Tenet would later write.

After 9/11 no American president could responsibly ignore the steady stream of reporting we were getting about the threat posed by Saddam Hussein. We had experienced an unprecedented attack on our homeland. Three thousand Americans, going about their everyday lives, had been killed. The president and I were determined to do all we could to prevent another attack, and our resolution was made stronger by the awareness that a future attack could be even more devastating. The terrorists of 9/11 were armed with airplane tickets and box cutters. The next wave might bring chemical, biological, or nuclear weapons.

When we looked around the world in those first months after 9/11, there was no place more likely to be a nexus between terrorism and WMD capability than Saddam Hussein’s Iraq. With the benefit of hindsight—even taking into account that some of the intelligence we received was wrong—that assessment still holds true. We could not ignore the threat or wish it away, hoping naively that the crumbling sanctions regime would contain Saddam. The security of our nation and of our friends and allies required that we act. And so we did.

* * *

Mr. Cheney writes that future U.S. leaders should learn from the nation’s failed efforts to contain North Korea’s nuclear weapons program. He says he believes the U.S. should have destroyed a nuclear reactor under construction in Syria, a facility ultimately bombed by Israel:

The story of our diplomacy with North Korea, particularly in the second term of the Bush presidency, carries with it important lessons for American leaders and diplomats of the future. First is the importance of not losing sight of the objective. In this case, the president had made clear that our goal was getting the North Koreans to give up their nuclear weapons program. However, as negotiations proceeded, the State Department came to regard getting the North Koreans to agree to something, indeed anything, as the ultimate objective. That mistake led our diplomats to respond to Pyongyang’s intransigence and dishonesty with ever greater concessions, thereby encouraging duplicity and double-dealing. And in the end it led them to recommend we accept an agreement that didn’t accomplish the president’s goal and even set it back….

This leads to the second and related lesson. The most effective diplomacy happens when America negotiates from a position of strength. If we remember that our ultimate goal is the substantive one of denuclearization and we are willing to walk away rather than accept a partial, untrue, or damaging agreement, we are in a much stronger position. At the same time, if our adversaries understand we will not compromise on fundamental principles and that we will use military force if necessary, they are much more likely to do business at the negotiating table.

That is why I argued that we should have taken action ourselves to destroy the North Korean–built nuclear reactor in the Syrian desert. It would have sent an unmistakable message to the Syrians, the Iranians and the North Koreans that our words meant something, that we would not tolerate the proliferation of nuclear technology….

The third lesson is that red lines must mean something. In the aftermath of 9/11, President Bush put in place an effective nonproliferation policy that yielded results. We dedicated ourselves to preventing terrorists and terror-sponsoring states from acquiring weapons of mass destruction. When the North Koreans tested a nuclear weapon in October 2006, President Bush warned that we would hold them fully accountable for the consequences of any proliferation, especially to states like Syria and Iran. Six months later, when we discovered they were proliferating to Syria, we should have held them accountable and did not. The lesson for other rogue nations might unfortunately be that they need not worry about threats from America….

Fourth, effective diplomacy requires that we think strategically. The president did just this when he insisted in 2001 that we get the Chinese engaged in our efforts to convince the North Koreans to give up their nuclear program. We also brought in the Russians, the Japanese and the South Koreans. The president saw that North Korea was already so isolated and under such extensive sanctions that the United States alone had little ability to bring significant pressure to bear. However, a multilateral approach that included China might well have the ability to pressure Pyongyang. We lost opportunities to encourage the Chinese to play a more constructive role. In the immediate aftermath of North Korea’s nuclear test in October 2006, for example, the Chinese were upset, particularly because Pyongyang gave them only an hour’s notice of the test. We should have used that moment of leverage to bring our partners in the six-party talks together—with the Chinese in the lead—to put true pressure on the North Koreans….

Fifth, America’s position in the world is strengthened when we stand with allies. In this instance we failed to do that, instead sidelining two key allies—the Japanese and the South Koreans—in our bilateral dealings with the North….

Finally, effective diplomacy requires that our diplomats study and learn from our history. In this case, recent history with North Korea was a pretty effective guide to how they would behave.

They signed the Agreed Framework in 1994 during the Clinton administration and immediately began violating its terms, demanding payment and looking for ways to use the negotiations to blackmail the United States….They behaved the same way with us and have brought out all their threats and demands again for the Obama administration. They have learned now, through Republican and Democratic administrations, that this is an effective way to operate. It yields concessions from the West while they continue to develop nuclear weapons. I hope a future president and secretary of state will break the cycle. This is particularly important because in the area of nonproliferation, as in so much else, the United States must lead. If we do not hold the line, few others will.

“In My Time: A Personal and Political Memoir,” by Dick Cheney with Liz Cheney. Copyright 2011 by Richard B. Cheney. Published by Threshold Editions, a division of Simon & Schuster Inc. Used by permission.