The US Defense Department released video Friday it says depicts the entire confrontation last Sunday between US and Iranian naval forces in the Gulf. The more than half-hour video, shot by a crew member on the bridge of the destroyer USS Hopper, was unedited, said, Pentagon spokesman Bryan Whitman. The often uneven and grainy video shows crew members answering radio calls and monitoring the five Iranian boats and for much of the time follows one or more of the fast boats moving around the US ships. It chronicles crew members communicating with each other on the Hopper, as well as US crew on the other two ships in the convoy. And as the incident escalated, sailors can be heard growing more agitated about how fast and close the small boats were moving near the ships. The Pentagon released the entire video of the event after days of fielding questions about the origin of a voice on the initial video that warns in English: "I am coming to you" and then, "You will explode after ... minutes." Less than five minutes of the video footage was released Tuesday. The confrontation reflects a shift in military strategy by Teheran to use its Revolutionary Guard's fast boats in a more aggressive manner in the region, the top US military officer said Friday. And while Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, said he could not himself tell if verbal threats heard in a US-aired tape of the confrontation actually came from the Iranian boats, he said the clash was the most "provocative and dramatic" he has seen to date. "The incident ought to remind us all just how real is the threat posed by Iran and just how ready we are to meet that threat if it comes to it," Mullen said. Sunday's incident ended peacefully with no shots fired, the US military said. In December, however, the Navy said Friday one of its ships fired warning shots at a small Iranian boat in the Strait of Hormuz during one of two serious encounters that month. The amphibious warfare ship USS Whidbey Island fired the warning shots on Dec. 19 in response to a small Iranian boat that was rapidly approaching it, said a Navy official, who spoke on condition of anonymity because of the sensitivity of the issue. In the second incident that month, the guided missile frigate USS Carr encountered three small Iranian craft on Dec. 22, two of which were armed, said the official. The Carr fired no shots but sent warning blasts on the ship's whistle, which caused the boats to turn around. The reports come a day after the United States lodged a formal diplomatic protest with Iran over Sunday's incident. Adm. William J. Fallon, the top US military commander in the Middle East, said Friday that Iran runs the risk of triggering an unintended conflict if its boats continue to harass US warships in the strait.