In centuries past, governments, both good and bad, could hide secret projects and troop movements from prying eyes. Armies would fight over mountaintops or float balloons to get a visual advantage.
The airplane changed the rules of the game. Spies on the ground could locate a target; reconnaissance planes could then photograph it. But both balloons and aircraft could be brought down by ground fire.
Today, spy satellites are (so far) beyond the reach of ground- based weapons. US surveillance ability was a big trump in the Gulf War and Kosovo. Arms-control agreements rely on each side's confidence that it can verify what the other side is up to.
With the Sept. 24 launch of Space Imaging Inc.'s IKONOS-2 satellite, photography once available only to intelligence agencies will be on sale by year's end to the public, the media, and anyone else willing to pay. The detail in these photos - showing objects as small as one yard wide - goes far beyond anything viewers have yet seen on their TV screens or the Internet.
And that makes American national-security officials antsy. They worry that a potential enemy or terrorist group could obtain useful information to plan attacks or defend against US military strikes.
In 1994 President Clinton ordered private satellite companies to submit to "shutter …