The United States said on Thursday it would be a waste of time to challenge the way it was awarding contracts to rebuild Iraq, after Europe raised deep concerns. "There is a substantial basis for doing it the way we have done and I do not think that it is worth spending one's time challenging it," State Department spokesman Richard Boucher said. "There is a lot of work to do in Iraq. It is time to get on with that work," he told reporters. Brussels had said there were grounds for concern that companies based in the European Union were...