America faces a heightened risk of attack this summer and must be more vigilant, warned Homeland Security chief Michael Chertoff, who told the Chicago Tribune he has a "gut feeling" al-Qaeda is mobilizing. "We worry that they are rebuilding their activities," he said. A report from his agency earlier warned of a summer terror "spectacular."
Al-Qaeda statements and intelligence point to a heightened "vulnerability," but aren't concrete enough to raise threat levels, Chertoff added. He warned against resistance to controversial border security measures backed by the Bush administration. "If you get to complacency, I guarantee we will lose the race with the terrorists," he said. (Read more Michael Chertoff stories.)