Shortly after Hurricane Katrina devastated New Orleans, Speaker of the House Dennis Hastert wondered aloud whether the Federal Government should help rebuild a city much of which lies below sea level. The most tough-minded answer to that question demonstrates that rebuilding and protecting New Orleans is in the national interest. Reason: The very same geological forces that created that port are what make it vulnerable to Category 5 hurricanes and also what make it indispensable.
One such force is the Mississippi River. Once, the Gulf of Mexico extended north to Cape Girardeau, Mo., but the river gradually deposited enough sediment into...