Five centuries ago, the powerful Ming Dynasty built the 1,500-mile wall, that period's equivalent of the president's proposed missile defense shield.

While impressive in scope even today, the Great Wall failed to prevent a foreign incursion that directly led to the fall of the Ming. Nomadic Mongol tribes, "rogue states" on the northern frontier, constantly plagued Ming leaders, arriving in Chinese cities, sometimes to raid but just as often seeking to trade.

As historian Arthur Waldron has shown, some Ming leaders advocated increased trade to help placate the Mongols, while others called for aggressive military campaigns.

The military option proved initially successful, but the leadership found it difficult to sustain political support. Gradually, Ming leaders began to implement a strategy used with some effectiveness in the past: spending huge sums to build defensive walls.

While a deterrent, the Great Wall did not defend against a previously unforeseen threat from Manchu tribes that eventually breached it, not through military force, but with the aid of Chinese generals who invited them into their territory to help quell local rebellions.

Today's nuclear-armed intercontinental ballistic missiles have transformed military strategy and defense. Yet, does the existence of those missiles change one of the lessons of the Great Wall -- the fact that the victorious Manchus did not directly attack the wall, but rather used diplomatic maneuvers and unrest within China to breach it?

The terrorists that savagely attacked New York City and Washington, D.C., on September 11 did so by circumventing established security barriers, taking over domestic flights and using them as tools in their hideous attacks.

If the missile defense shield is built, is it not reasonable to conclude that terrorists and rogue states will find ways around that shield as well?

I am not suggesting that the United States abandon sophisticated military defense systems. Rather, instead of building the massive missile defense shield, it seems more prudent to take a long-term, proactive approach by finding ways to lessen the anti-American sentiment that fueled recent terrorist attacks.

Waldron notes that a 15th-century Ming official concluded that the Mongols were a calamity for China only because they desperately needed clothing and food.

President Bush suggested that the terrorists responsible for the September 11 attacks were motivated by hatred for American freedom and our way of life. While this may be true, it is also clear that anti-American movements have been fueled by economic hardship in various parts of the world.

With a mere fraction of the money spent on the missile defense shield, the United States could build more schools, water purifying plants and other infrastructure in Afghanistan and perhaps Palestinian areas, alleviating some of the desperation of the people there. Such moves would also provide greater regional economic stability and in turn, engender goodwill toward the United States.

More importantly, the terrorist groups would have more difficulty recruiting in those areas. Economic aid is not a panacea and will not eliminate the ideological and religious divisions that also fuel terrorist activities.

Yet, as the Great Wall teaches us, huge fortifications such as the missile defense shield have not proven effective in the long term. Should we believe that a wall in space would be any better?

In his Sept. 6 news conference with Mexican President Vicente Fox, President Bush asserted that "fearful people build walls. Confident people tear them down."

Americans should have confidence in the goodwill that our economic largesse can provide. More than a missile defense shield, a Great Wall of the 21st century, economic aid should provide a way to obviate the root factors of the terrorist threat that now grips our nation.

Robert Hellyer is an assistant professor in history at Allegheny College in Meadville, Pa. He specializes in East Asian history.

©2001 San Francisco Chronicle

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