British Prime Minister Tony Blair said he was relying on diplomacy to free sailors captured by Iran. But at the same time he noted that he would move on to “another phase” if diplomacy did not help. On March 23, Iranian authorities detained 15 British nationals on the border with Iraq; they may be charged with illegal border crossing and espionage. The situation is complicated by the fact that the border in the detention area is not precisely defined and Iran claims that part of the waters of the Shatt al-Arab River that Iraq considers its own.