"In these difficult times for America, I believe women have a contribution to make to move our country toward peace, prosperity and progress," Braun told supporters at her alma mater, the University of Chicago Law School.
Braun, 55, who ran into trouble during her Senate tenure for associating with Nigerian dictator Gen. Sani Abacha and questions over her handling of her mother's nursing home bills, accused the Bush administration of squandering the goodwill for the war on terrorism that accrued after the Sept. 11, 2001, terrorist attacks on Washington and New York.
"Rather than fritter that goodwill away in a rush to preemptory, unilateral military action and in the process isolate us in a country on perpetual alert, we would do well to foster cooperation to freeze the very ground in which extremism and terrorism festers," the former ambassador to New Zealand said.
" ... (Iraqi leader) Saddam (Hussein), (Osama) bin Laden and all their pals can and must be driven out of business and the world wants to see us succeed in that endeavor. But duct tape is no substitute for diplomacy and I believe the people can and must demand an end to the saber rattling that has made us hostages to fear."
Braun said the economy is suffering because of "failed leadership" and called the president's budget and tax cut policy "shortsighted."
"I believe that our country deserves leadership with vision," Braun said.
The former senator spent the weekend campaigning in the early presidential test states -- New Hampshire, Iowa and South Carolina.
She had planned to file the papers establishing the exploratory committee Tuesday but was thwarted by the snowstorm that shut down the federal government. A spokeswoman said the papers would be filed Wednesday.
Braun expects to kick off her campaign formally after Labor Day.
Braun, a former federal prosecutor, was first elected to the Illinois House in 1978, where she became the first woman and first black to serve as assistant majority leader. While in the House, she spearheaded efforts to keep the state from investing funds in South Africa because of apartheid. In 1987 she ran for Recorder of Deeds and became the first black woman to hold executive office in Cook County.
She defeated incumbent Sen. Alan Dixon in the 1992 Democratic primary in a backlash against his vote to confirm Clarence Thomas to the U.S. Supreme Court. She then went on to defeat the Republican challenger, Richard Williamson.
While in the Senate, Braun served on the Judiciary, Banking, Housing and Urban Affairs, and Small Business committees.