President George W. Bush said Monday the Iraq war is "straining the psyche of our country" but leaving now would be a disaster. Bush served notice at a news conference that he would not change course or flinch from debate about the unpopular war as he campaigns for Republicans in the November congressional elections. In fact, he suggested that national security and the economy should be the top political issues, and criticized the Democrats' approach on both. Many Democrats want to leave Iraq "before the job is done," the president said. "I can't tell you exactly when it's going to be done," he said, but "if we ever give up the desire to help people who live in freedom, we will have lost our soul as a nation, as far as I'm concerned."