George W. Bush: 'Very Comfortable' with Decision to Invade Iraq As museum opens, ex-president sees mission in expanding on work of presidency.

UNIVERSITY PARK, Texas, March 24, 2013  -- As his presidential library and museum open, former President George W. Bush said he remains "very comfortable" with perhaps the most controversial decision of his presidency -- the invasion of Iraq -- as he pursues a post-presidency removed from the spotlight but active on a series of core issues.

In a wide-ranging interview that touched on everything from his brother Jeb Bush's presidential prospects, the Republican Party's future, and his new passion for painting, he told ABC News' Diane Sawyer he hopes the library and museum serve as resources for historians to judge him based on the same facts he had access to as president.

That includes his decision to invade Iraq, despite the fact that the world later learned that Saddam Hussein did not have weapons of mass destruction. The museum presents that information directly, Bush said.

"We're just laying out the facts. And that was a fact," Bush said. "I am comfortable in the decision-making process. I think the removal of Saddam Hussein was the right decision for not only our own security but for giving people a chance to live in a free society. But history will ultimately decide that, and I won't be around to see it.

"As far as I'm concerned, the debate is over. I mean, I did what I did. And historians will ultimately judge those decisions."

As the formal dedication of the George W. Bush Presidential Center takes place Thursday, Bush appears at ease with both his much-lower profile and his handling of the major episodes that defined his presidency. President Obama and all four living former presidents, including George W. Bush's father, plan on attending the ceremony just outside Dallas.

The younger Bush's post-presidential efforts are aligned with some of the more popular initiatives of his presidency -- fighting AIDS in Africa and empowering women in the Middle East, for example. The new museum, like Bush's memoir, "Decision Points," focuses intensely on critical periods of his presidency, including 9/11, the run-up to the Iraq War, Hurricane Katrina and the 2008 financial crisis.

As a brand-new grandfather who says he's now painting daily, Bush said those who wonder if he has sleepless nights about the decisions he made as president shouldn't worry.

"No, sleeping pretty well," Bush said. "It's nice of 'em that [they] can be concerned about my sleeping habits, but ... I'm rested. I know I'm rested."

The presidential center, set on a sprawling 23-acre site on the campus of Southern Methodist University, houses the Bush Library and Museum as well as the Bush Institute. The institute, founded in 2009, builds on the principles of the Bush presidency through research and training on economic growth, education reform, global health, human freedom, wounded veterans, and helping women in the Middle East.

"Through the Bush Institute," former first lady Laura Bush said, "we've had the chance to continue to work on the issues we think are so important, that were important to us when George was president and that we want to work on, really, for the rest of our lives."

The library and museum house the papers and records of the Bush presidency -- including more than 200 million emails, 70 million paper documents and 43,000 artifacts, including Saddam Hussein's gun and the bullhorn Bush grabbed at Ground Zero.

The museum is a history of the former first family, as well as Bush's turbulent eight years in office, featuring everything from a giant chunk of mangled steel from the Twin Towers to a portion of the signed baseball collection Bush began accumulating as a child.

The centerpiece is the "Decision Points Theater," which presents a series of critical decisions the president was faced with, and asks the visitor to make a snap judgment based on that information.

"The purpose of the museum is not to herald me, necessarily, but to explain different events and to show people what it's like to make decisions," the former president said. "And the other message in the museum is to encourage people to serve. One of the really unique features of America is the millions of acts of kindness that take places on a daily basis. And I really think it's an important part of our country and will continue to be important part of our country."

A key message, Laura Bush said, is that the president needs to make countless high-impact decisions, and fast.

The idea, she said, is to "feel the pressure that the president feels. ... The president is a man who makes good decisions and sometimes doesn't. I mean, that's just the fact of life like every single one of the rest of us."

The presidential center opens at a time of broad reevaluation of the Bush legacy. A large cadre of former aides who've descended on Dallas for the museum opening have expressed hope that the a presidency perhaps best remembered now for two wars, an economic crisis, and the aftermath of Katrina will also be recalled for work combating AIDS, expanding seniors' access to prescription drugs, and pressing for immigration reform, just for starters.

A new ABC News/Washington Post poll out this week found that 47 percent of people approve of the job Bush did as president, with negative sentiment softening considerably over the past few years. While 50 percent still disapprove, Bush hasn't seen approval ratings this strong since December 2005 -- less than a year into his second term.

The dedication also comes as national events such as the Boston Marathon bombings stir memories of a defining episode of the Bush presidency -- Sept. 11, 2001. A few days after the Boston attack, an explosion at a fertilizer plant not far from Bush's own Texas ranch stoked fears of further terrorism.

Related: Bush: Boston Attacks 'Harkened Back' to His Presidency

"Whether it be that [attack at the Boston Marathon] or the explosion at West, Texas, I mean -- it hearkened back to days where you become the comforter-in-chief, you try to help heal souls that that are hurting," he said.

The former president told Sawyer that he's comfortable staying far away from day-to-day politics, in contrast with his predecessor, Bill Clinton, and his former vice president, Dick Cheney. He declined to weigh in on raging debates over immigration reform, gun control and gay marriage, saying: "You're either in or out."

"I had all the fame I needed -- and I am trying to be not famous," he said. "I don't really want to undermine our president. And frankly, the only way for me to generate any news is to either criticize the president or criticize my party. I'm not interested in doing either."

He added: "I know people don't believe that. I guess they have trouble believing that somebody who's been in the limelight for so long is anxious not to be in the limelight."

Related: George W. Bush Tells Jeb 'Run!' in 2016

He is making an exception to advocate for the presidential candidacy of his younger brother, Jeb Bush, a former governor of Florida.

"He'd be a marvelous candidate if he chooses to do so. He doesn't need my counsel 'cause he knows what it is, which is, 'run,'" Bush said.

Related: George W. Bush: 'Painting Has Changed My Life'

Painting now occupies part of every one of the former president's days, and is giving him an opportunity to "keep learning in life," he said.

"Painting has changed my life in an unbelievably positive way," he said.

The Bushes became grandparents for the first time just this month when their daughter, Jenna Bush Hager, delivered a daughter, Mila. Asked what he wants to be called by his grandchildren, the former president joked, "El Jefe" -- Spanish for "the chief" or "the boss."

"I will tell you this, holding that little child was one of the great joys of my life," he said. "Holding little Mila was unbelievably pleasurable. And I'm looking -- I really am looking forward to this new phase of our lives, which is being a grandfather. ... I plan on spoiling the child."

Family will be on Bush's mind Thursday as well. His father, George H.W. Bush, now 88 and in frail health, will be among the former presidents in attendance. In a courtyard at the museum, there's a statue of the 43rd president side-by-side with his father, the 41st.

"He's meant a lot to me in my life," the younger Bush said. "I wouldn't be sitting here without his unconditional love. And it gives me great comfort to know that he will be by my side for eternity."