It's hard to believe, now that it's been overrun by 7 million residents and 7 jillion strip malls, but southern Florida was once America's last frontier. As late as 1880, the census recorded just 257 residents in a county covering most of the region -- because most of the region was a watery wilderness called the Everglades. Mapmakers weren't sure whether to draw it as land or water. Politicians dismissed it as uninhabitable swampland. Explorers described it as a "godforsaken" and "hideous" and "abominable" morass, "suitable only for the haunt of noxious vermin, or the resort of pestilential reptiles." When …

Dam, that's a pretty lock: the sun sets behind the Corps navigation structure at Alton, Ill. Photo: Mark Hirsch Imagine the Pentagon had been caught red-handed concocting its justification before launching the invasion of Iraq in 2003. Imagine that after the scandal died down, the Pentagon admitted Saddam didn't really have WMDs -- but proposed an even larger invasion, because there was a remote possibility things might change someday. Then imagine Congress had rewarded this logic with overwhelming bipartisan support. It's a silly thought experiment, because Congress -- for all its flaws -- takes war at least somewhat seriously. But …

The fate of this navigation channel on the Louisiana coast, shown in 1970 (left) and 2001, offered a glimpse of things to come. Photos: White House OMB  If an unsafe building collapsed and killed 1,000 people, we wouldn't blame the building's manager, even if he bungled his evacuation plan, or its maintenance crew, even if they had shirked their jobs before the disaster, or the rescue squad, even if it was terribly slow to respond. We wouldn't shrug and blame Mother Nature. And we certainly wouldn't blame the victims -- especially if they had been assured the building was safe. …