Students who are interested in learning about the environment should not be dissuaded from doing so, but only if they have proved their proficiency in other basic courses, such as U.S. history. Until then, we need to focus on producing well-educated citizens steeped in their country's history and mindful of their civic responsibilities.

If succeeding generations of Americans don't understand the concepts of justice, individual rights, free enterprise, capitalism, sovereignty or national security, there can be no guarantee that those concepts - or others like them - will continue.

From computers to information technology to airplanes, it has been America's unique blend of republican government and free-market capitalism that has allowed us to surpass all other nations in history.

Securing freedom has been a singular commitment of American presidents and patriots in and out of government for generations. But its perpetual continuation is not guaranteed.