MIDDLE EAST - The United States is concerned that a "miscalculation" by Iran could cause an "unintended conflict" in the Gulf, as it prepares to launch a new surveillance and intelligence initiative with its allies to ensure "free and open passage" for ships. "We are starting a concept called Sentinel in which we will have a series of countries engaged to preserve the free and open passage of commerce in the Strait of Hormuz and in the Persian Gulf," US Under Secretary of Defense for Policy John Rood said at the Aspen Security Forum on Saturday. The US has had discussions with NATO allies, some "partners in the Gulf" and others to join the effort to keep the "vital waterway" open, said Rood, adding that the new operation would "come into being over the coming days and weeks". Will tension in the Gulf spiral out of control?