Iranians may be ruled by an oppressive regime and a tightly controlled economy, but apparently they know how to use Photoshop.

Thanks in large part to the Web site LittleGreenFootballs.com, a photo originating from the media arm of Iran's Revolutionary Guards this week was identified as being doctored. But not before large newspapers, such as The New York Times, had published it as real.

The photo showed four missiles being launched simultaneously. Iran clearly wanted to press a point about its military strength leading up to possible negotiations with the European Union. But one of the missiles apparently isn't real. It was a copied image. Agence France-Presse said it apparently was put there to cover up a missile that may have misfired during the test.

The firing of three missiles may have served Iran's purposes just as well, especially being accompanied, as it was, with claims that Iran has the capability of striking at Israel. Instead, however, the doctored photo provides some interesting lessons.

The first is that Iran's leaders are given to exaggeration to further their cause. While that is hardly earth-shattering news, the public outing of the photo has severely damaged the credibility of any other claims Iranian leaders may make about themselves.

Another is that the United States has hit its mark by signing an agreement to place radar interceptors in the Czech Republic and missiles in Poland as part of missile shield system. Missile defense has been a shaky proposition from the start, in terms of its effectiveness. But Iran clearly sees it as a threat. Conventional wisdom says the way to overwhelm such a system is through multiple simultaneous missile launches, such as what Iran attempted to picture.

Perhaps a bigger lesson is for the world at-large. Do not believe any image or video thrust your way, not matter how convincing it may look. The Internet is full of such things. The Web site YouTube, for example, features videos of people using vibrating cell phones to pop popcorn, of a ball-girl making a spectacular catch in foul ground during a minor-league game, of a man kicking a 110-yard field goal, and of incredible basketball shots that bounce off rafters and walls before swishing.

These are harmless fun, but they also are edited in convincing ways that were unavailable to average people a few years ago. Getting tricked by a funny video is one thing. But nations must be extra vigilant when assessing the claims of belligerent nations.