After the Iranian government bragged on Sunday about shooting down an unmanned U.S. plane, the Pentagon issued a somewhat cryptic statement that contradicts the claim. According to the AFP, Pentagon spokesman Captain John Kirby said on Monday that "we don't have any indication that the UAV that we know we no longer have was brought down by hostile activity of any kind." The official word matches what an anonymous source told Reuters on Sunday: "There is absolutely no indication up to this point that Iranians shot down this drone." The Iranian army recovered the downed drone, and while we won't know what actually happened for a while (if ever), the recent spike in troubling news from Tehran casts a shadow over the future of American-Irani relations. Michael Hirst reports at the National Journal

Two incidents that occurred on Sunday--Iran's claim of a shoot-down of a U.S. drone, and an explosion outside the British embassy in Bahrain--may have been unrelated. But they appear to add to growing evidence that an escalating covert war by the West is under way against Iran, and that Tehran is retaliating with greater intensity than ever. … The White House declined to comment but officials did not seem unduly alarmed, suggesting that the drone's capture would not provide Iran with significant information about U.S. surveillance technology and techniques.

While it's encouraging to hear that the U.S. government is staying cool about the incident, Iran sounds upset. One report from the Fars news agency reports that an anonymous military official has warned that Tehran's response to the U.S. aircraft flying over Iran "will not be limited to the country’s borders."