WHEN YOU read about "national security" in the columns, testimony, debates and public discourse of today, the phrase is often used narrowly as a synonym for "national defense" -- and employed reverentially to justify budgets, policies, overt and covert actions, successes and sometimes failures. But it means more than that.

The term "national security" came into general usage somewhere between the National Defense Act of 1920 and the National Security Act of 1947. The country had evolved from relative isolation to an important place in international affairs. As this occurred, we came to understand that the security of the United States was a newly complex and all-encompassing issue. It was domestic as well as international, at stake in peacetime as well as war, concerned with the values as well as the valuables of our country, and it involved nearly every aspect of national life and effort. It concerned soldiers and diplomats, but much more.

For a long while our thoughts about national security had been chiefly internal in focus -- we were oceans away from most other people; horses and sailing ships measured the pace of our transport; and communications were so rudimentary that mail about overseas problems often reached America after the events had passed. Moreover, we were not enough of a factor in the world to spend time devising new terms or integrated stategies.

In this century, however, things changed: the world grew "smaller," its problems larger, and people everywhere were drawn into a dangerous closeness by population growth, increased mobility and scientific invention. Along with this, the American role on the world stage expanded, and with increased responsibilities came increased national attention to world affairs and international security.

When it comes to the national defense component, we need strong military forces, trained and motivated military people, thoughtful and responsible leaders and the best of modern equipment.

But we also know that the "threats" to our security are not simply military. Stability, world order, peace and freedom are equally endangered by such threats as: hunger, disease and unemployment; a lack of housing, over-population and crowding; unequal opportunity and injustice; scarcity of resources; brutal tyrannies of the left and the right; both covert and overt aggression; old enmities, new frictions and emerging aspirations for a place in the sun; the destabilizing impact of change itself.

Diverse and complex as it is, national security in a free society involves us all. It is the child of many parents; it is everyone's business. It is not too "secret" for Congress, not too arcane for everyday citizens, or the sole business of a security elite. It is the concern for all the American people.

Ideally, if not always in reality, our defense and foreign policies should reflect the best values of our society and rest upon a set of fundamental strategic concepts. What are some of these pillars on which we base our defense?

National values. Their clearest expression is still found in the Declaration of Independence, the Constitution, the Bill of Rights and the amendments which have reflected our later experiences. The timeless wisdom and eloquence of an earlier day still inspire and guide us. Our roots were good and strong, and they have strengthened over the years.

Vital interests. It is important to identify them in enduring essence rather than transitory detail. So what are the truly vital interests of our country? I suggest these: the lives of our citizens; the sanctity of our lands; our individual freedoms, and the political institutions which make them possible; the national economy and our natural resources; freedom of the seas and skies, and free access to markets, resources and friends; the security of our people, friends, investments and installations overseas; peace as an ideal, a goal and an increasing necessity, but not at the price of freedom and justice; and finally, a commitment to stand with friends on behalf of human dignity, human rights, freedom and justice.

That may sound like nothing but "motherhood" -- obvious, incontestable, but imprecise and not tailored to the harsh and specific realities of the instant. But I do not agree. We must set our compass on fundamental, unchanging objectives. Based on them, we can adapt to momentary circumstances. But we get into trouble when we try to devise "Napoleonic Codes" in advance, or define every hot spot or transitory irritation as "vital." We need to be stable, thoughtful and far-sighted in our judgments as to the vital interests of the nation.

Those of you who will soon be lieutenants may think there is a wide gulf between the issues I have been discussing and the immediate challenges of an infantry or tank platoon, an artillery battery, flying a helicopter, bridging rivers or supporting our forces with energy and technical competence. But to be a leader in the armed forces of a free and democratic nation requires an exceptional depth of purpose and understanding. On the lapels of your uniform you will wear U.S. insignia. They are reminders that you represent as well as serve the United States, a serious and profound responsibility. If you bear true faith and allegiance to that concept, you will deserve the salutes you will receive.

Recent events remind us that as one progresses upward in the military, it is important to guard against the heady temptations of power. Whatever the facts with respect to specific individuals and acts, we need to focus on such things as these:

Lying.

Forgetting loyalty to an oath and a Constitution.

Ignoring the rule of law in favor of the rule of men.

Runaway egos.

Self-righteousness.

Ideological zealotry.

Breaches of faith.

Abuses of position and power.

Using unacceptable means to achieve ends which may or may not be acceptable.

Undercutting the Congress.

Involving the military in partisan politics, and meddling in foreign policy.

Selling out for status, and sometimes for money.

I needn't tell you that all are intolerable, and largely unforgivable in public servants of a free society in whom "special trust and condfidence" has been reposed.

But while these are matters of serious concern, it is important to remember the honorable majority who do live up to their trust and who find a special selfless satisfaction as leaders in the American armed forces. This was eloquently expressed by Gen. Creighton Abrams in a last speech which fate did not give him time to deliver. Addressing the Army and the American soldier's role, he wrote, "There must be, within our Army, a sense of purpose and a dedication to that purpose. There must be a willingness to march a little farther, to carry a heavier load, to step out into the dark and unknown for the safety and well-being of others."

Over the long years since I first became an infantry private, that sense and opportunity have always inspired me. I hope that you, too, will come to know the pride to be found in such service. It is unique to soldiers who serve free societies. They share the humane values of the people they serve, and join with their fellow citizens in creating a national security which rests not alone on armed stength but also upon the special virtues of freedom, justice and opportunity.

DeWitt Smith is a retired lieutenant general in the U.S. Army. This article is based on a speech he delivered in April to the George C. Marshall ROTC Award Seminar in Lexington, Va.