The �star� of the Olympics may not be multiple medalists but the Great Wall of China. Every TV network covering the Olympics took the world to see the Wall. It seemed as if almost every newspaper and magazine reporter also visited the Great Wall.

But, the Great Wall, which was built and rebuilt many times over its 22 century history, eventually was a failure. Although formidable, and one of the world�s greatest engineering feats, the wall by the 16th century could no longer protect China from neighboring armies.

The Maginot Line, which France thought could protect it from Germany and Italy in the decade leading up to World War II, was largely a failure.

The Berlin Wall, at first barbed wire and then concrete, was built not to keep others out but East Germans in. But, there were more than 5,000 escapes during its 28-year history before the wall finally came down in 1989.

As we now know, poorly constructed levees in New Orleans didn�t keep the flood waters of Katrina from destroying the city.

And now the U.S. is building its own wall. The Bush administration is putting up about 700 miles of fencing and other barriers along the U.S./Mexico border by the end of the year. The cost just to build that barrier is about $2�$3 million per mile. But, in certain places, the cost far exceeds that. This week, the government began excavating an area near San Diego. When the three and one-half mile fence is finished, the cost will be about $57 million. That�s about $16 million a mile.

Most illegal immigrants pose no problems. They don�t receive American benefits, contrary to a lot of Internet gossip. Most try to avoid getting into trouble, since their purpose of being in America isn�t to get noticed by the police. And, for those who think putting up a wall will keep terrorists out of the country, reflect upon this: The 9/11 hijackers had American-issued visas to be in the U.S.

Like the Great Wall, the Maginot Line, the Berlin Wall, and the levees, this wall will also fail, as persons desperate to enter the U.S. will find many other ways to cross the border. But, Americans will have spent more than $2 billion for that lesson.