WASHINGTON - A turf war between the two senior intelligence chiefs over the role of CIA station chiefs in U.S. embassies has forced National Security Adviser James L. Jones to step in to mediate, according to current and former U.S. government officials. The jockeying between CIA director Leon Panetta and National Intelligence Director Dennis Blair centers on Blair's effort to choose his own representatives abroad instead of relying only on CIA station chiefs, the current and former officials said. They spoke on condition of anonymity because of the sensitivity of the dispute.