As we observe the eighth anniversary of al-Qaida's attack on our nation, I propose that we imagine ourselves under attack, albeit a more insidious, less spectacular one.

No, I'm not trying to spread unhappiness. I am instead hoping we can use the memory of that tragic day to improve our lives and those of our children.

The date of Sept. 11, 2001, is seared into my memory. When I first saw a plane fly into a building, I thought it must have been an errant commuter-plane accident.

As we all now know, it was not a commuter plane but a commercial jetliner. Not an accident, but a coordinated attack by terrorists determined to die for their beliefs. Young terrorist men, 19 of them, died that day. They took the lives of almost 3,000 Americans and the naivete of a generation of others.

Six weeks before the tragic day, I gave birth to my second child. My nights were sleepless after the attack, from rocking him to sleep in the early hours, and from newfound anxiety. Listening to the military aircraft fly over our home in Atlanta -- a few miles from Dobbins Air Reserve Base -- I worried about his safety and the world in which he would grow up.

"We have come together with a unity of purpose because our nation demands it," The 9/11 Commission Report said. It continued, "The nation was unprepared."

No one is ever prepared for tragedy.

"The most important failure was one of imagination," noted the report. "We do not believe leaders understood the gravity of the threat."

"Imagination," according to Albert Einstein, "is more important than knowledge."

Imagine our enemies infiltrating our internal structures and causing our nation's health, economic and educational systems to deteriorate. Even if they haven't, what if we responded as if they had, thereby creating a unity of purpose -- to make America better?

Many of our nation's core areas are indeed under threat. It is up to us to understand the gravity of those threats and to respond.

In the area of health, we must solve our nation's underlying health crisis. In the United States, more than one-third of adults are obese, according to the Centers for Disease Control and Prevention. Obesity creates an enormous burden on personal health (it often leads to other health issues) and on our nation's health. The cost of obesity might be as much as $147 billion per year, according to health economist Eric Finkelstein.

In education, we have almost "1.3 million students who will not graduate from high school with their peers," according to the Alliance for Excellent Education. The alliance estimates those dropouts will collectively lose "nearly $335 billion" over the course of their lifetimes. This must be addressed along with the quality of education. Americans are not able to reach their full potential -- this is a tragedy. Our children are our nation's future.

The economy is flagging, unemployment is rising and billions have been injected into our economic system. The government has propped up banks and companies. The underlying beliefs in capitalism are being undermined through government intervention. Our nation currently has "$56 trillion in unfunded obligations," according to David Walker, president and CEO of the Peter G. Peterson Foundation; this amounts "to $483,000 per household." We have an economic state that is not sustainable.

Since the terrorist attacks on the World Trade Center and Washington, our political climate has become increasingly partisan. Instead of meeting in the middle and working toward solutions, people are standing on the fringes and yelling at each other. We have forgotten that we share many common goals and should work on achieving these goals together.

"We call on the American people to remember how we all felt on 9-11, to remember not only the unspeakable horror but how we came together as a nation -- one nation," concludes The 9/11 Commission Report. "Unity of purpose and unity of effort are the way we will defeat this enemy and make America safer for our children and grandchildren."

Imagine if our enemies could infiltrate our nation's health, education and economic systems, and sow the seeds of our destruction. Would this not lead to our defeat and their victory? The way to success is by working together to make America better.

Let's not permit the tragedy of forgetting a tragedy. Let's work together to solve our nation's challenges.

Unity of purpose and unity of effort, may we never forget Sept. 11.