I first met Hillary Clinton in 1997 while I was the Senior Director for African Affairs at the National Security Council. The First Lady was best known at that time for leading the fight for health care reform, and her strong advocacy on behalf of minorities, children and women. Though new at the time to foreign policy, she had electrified the world in Beijing in 1995 when she declared at a United Nations conference: "Women's rights are human rights."

She was keenly interested in Africa, having recently returned from a visit there. Moved by that experience, she became a valued and persuasive partner in convincing President Bill Clinton to travel there the following year. It was an historic, substantive and precedent setting trip: six countries over eleven days, the longest period of time the President spent outside the country during his tenure.

In South Africa, Nelson Mandela, a hero to both Bill and Hillary Clinton, took them to see his jail cell on Robben Island, where he had broken rocks for 27 years as a convicted terrorist. The symbolism of his transition from prisoner to beloved liberator, leader and statesman was lost on nobody. No wonder Hillary Clinton has called him her most inspirational international leader.

Our last stop, Dakar, Senegal, was dedicated to African-Americans and the contributions they have made to American society, culture and economic achievement. Standing at the infamous "Door of No Return" at the House of Slaves on Goree Island, we were all touched by the terrible circumstances that had brought Africans to American shores in chains centuries ago.

As a senator from New York, Hillary sought out my views on U.S. policy towards Iraq after the invasion. I had been a vocal critic from the beginning of the debate, my opposition having been informed by my experience in Iraq as acting Ambassador during the 1990-1991 Gulf War. I had negotiated with Saddam Hussein and his government for the release of over 150 Americans he had held hostage, and was the last American diplomat to meet with him.

The Bush administration's dishonest but effective propaganda campaign in 2002 for an invasion played on the trauma of the terrorist attacks of September 11, 2001. Condoleezza Rice, the national security adviser, ominously warned that Saddam was aggressively developing nuclear weapons. "We don't want the smoking gun to be a mushroom cloud," she said. And President George W. Bush insisted that a congressional resolution was needed as leverage for the return of UN inspectors to Iraq to further explore whether Saddam possessed weapons of mass destruction.

The administration promised that it would seek explicit UN support prior to any military action. Meanwhile, every top official, including Secretary of State Colin Powell, assured senators that Saddam did indeed have WMD. It was in that context that the congressional vote for the Authorization for the Use of Military Force took place. Hillary has acknowledged in retrospect that her vote was an error. I agree. The error, however, was to believe an administration that has since been exposed as having serially lied to Congress, the American people and the world at the United Nations. We should never forget the extent to which the Bush administration betrayed our trust. The rest of the world doesn't.

During the U.S. occupation of Iraq, Hillary emerged as one of the administration's toughest critics. She traveled frequently to Iraq to observe the facts on the ground for herself and to speak directly to military commanders and U.S. officials. And she used her position as a member of the Senate Armed Services Committee to harshly question the disastrous Bush policy. She never flinched in her criticism. Not to acknowledge the full story of Hillary's record is to distort it.

Valerie's and my support for Hillary is owed as much to her character as to the issues. When I challenged the Bush administration on the truth of its case for war in a New York Times opinion piece in 2003, its reaction was to betray Valerie's identity as a covert CIA officer. The subsequent vicious attack on us by Republican partisans, designed to shift the focus from their crime was withering and unrelenting. Hillary repeatedly reached out to us with counsel and empathy as we navigated the shark infested waters. Speaking from her own personal experience, she reminded us of the importance of the good fight, however difficult it might be. Those who were attacking us, like those who had attacked her over the years, wanted to destroy people doing the right thing in order to discourage others from venturing into the public square. If they can't win on the facts, they invent smears to attack the characters of their critics. With Hillary's moral support, we stood up to the bullies. We could not give them that victory. She was right and we were vindicated.

Barack Obama, who has been a consequential president, has learned from his own experience in the White House just how hard meaningful change is to achieve. But in the face of venomous attacks and partisan sabotage that he did not expect when he began, he has managed to make real progress. It has taken a lot more work than repeating a mantra about "revolution." And that's one of the most important lessons of the Obama presidency. Defending and extending that change depends on electing a president committed to it. Hillary understands how to make progress, too. Time and again she has been tested. She has risen to every challenge, personal and political, from service on the key Senate Armed Services committee during war to leadership of the preeminent Cabinet Department at a time of deep suspicion around the world of our country. And she has grown in her leadership. Now she seeks to lead our country, the biggest challenge.

We stand with Hillary because of her stand on issues we care about, and because of her character and courage in standing for Valerie and me during the concerted campaign of lies and smears waged against us by the likes of Karl Rove -- who boasted that Valerie was "fair game." Hillary didn't have to help and openly associate herself with us. But she understood that we were right to stand up to the abuse of power, mudslinging and the twisting of American values, as she has persistently stood up so many times in her life. She supported us, and she trusted us. Now we support her, and we trust her.