Rather , the US acted because the administration saw " existing evidence in a new light , through the prism of our experience on September 11 " .
We acted because we saw the existing evidence in a new light , through the prism of our experience on 11 September , " Rumsfeld said .
The Standard & Poor 's 500 Index .SPX gained 13.68 points , or 1.42 percent , at 977.27 .