Rockefeller, who represents West Virginia, told CBS News that Saddam Hussein would have been "isolated" in Iraq.
"He would have been in control of that country, but we wouldn't have depleted our resources preventing us from prosecuting a war on terror which is what this is all about," Rockefeller said.
On Friday, the Intelligence Committee declassified a report that found no link between Saddam and al-Qaida. Rockefeller, who voted in favor of an Iraq invasion, accused the Bush administration of misleading the country before the invasion in 2003.
"The absolute cynical manipulation, deliberately cynical manipulation, to shape American public opinion and 69 percent of the people, at that time, it worked, they said 'we want to go to war.' Including me," he said. "The difference is after I began to learn about some of that intelligence I went down to the Senate floor and I said 'my vote was wrong.'"
Sen. Pat Roberts, R-Kansas, the committee chairman, has described the report as partisan.