While President George W. Bush acknowledges the need for major changes in Iraq, he will not use this week's Iraq Study Group report as political cover for bringing US troops home, his national security adviser said. "We have not failed in Iraq," Stephen Hadley said as he made the Sunday TV talk show rounds. "We will fail in Iraq if we pull out our troops before we're in a position to help the Iraqis succeed." But he added: "The president understands that we need to have a way forward in Iraq that is more successful." The White House readied for an important week in the debate over Iraq: Bush planned a meeting Monday with Abdul-Aziz al-Hakim, the Shiite leader of the largest bloc in Iraq's parliament, and awaited the recommendations Wednesday from the bipartisan commission. Yet his administration, hoping to find a new way ahead in Iraq, found itself on the defensive from the second recent leak of an insider's memo on Iraq in a week. The latest, first reported in Sunday's New York Times, showed that Donald H. Rumsfeld called for a "major adjustment" in US tactics on Nov. 6 - the day before an election that cost Republicans the US Congress and Rumsfeld his job as defense secretary. Hadley appeared on ABC's "This Week," NBC's "Meet the Press," and `Face the Nation" on CBS. Warner and Levin were on NBC, Biden was on "Fox News Sunday" while Feinstein appeared on "Late Edition" on CNN.