Today the president joins the debate that has been going on in this space over the merits of the MX missile.

In a matter of hours, the Congress will vote on a question of vital concern to all Americans-- one of the most important votes involving arms reduction it may ever be called on to cast. The debate on the MX Peacekeeper missile, and the whole issue of strategic modernization, has been on the front pages for months now and may seem to have reached its saturation point. But, as is too often the case, the nature of much of the debate has generated far more heat than light, and made it harder for many sincere citizens to reach a calm, reasoned decision.

In these final hours before the Congress acts, I want to state, clearly and directly, what is at stake, and why it is so important to our country and to the world our children will inherit from us. Most of us are already familiar with what the vote will be about. The specific legislative proposal is to approve flight testing of the MX Peacekeeper missile and the work needed to base it in existing Minuteman silos. This is the first essential step toward deployment of 100 Peacekeeper missiles beginning in 1986, and for the development of a new, small and mobile single-warhead ICBM--all part of a long-overdue modernization of our aging defense system.

But if the details of the debate are clear enough, its importance may not be. At stake is the future of arms reductions--balanced, verifiable arms reductions that can make the world of tomorrow a safer place for all the Earth's people. That is a goal all sensible people share, an issue that cuts across party and philosophical lines and unites us as Americans and as members of the human family.

When I endorsed fully the Scowcroft Commission's recommendations on the MX Peacekeeper and modernization, I did so because I was firmly convinced that they balanced the three keys to our country's present and future safety: modernization, to maintain state-of-the-art readiness against a much newer Soviet array of systems; deterrence, to continue to make clear to the Soviets that aggression on their part would never pay; and progress in arms reductions to move from a balance of terror toward stable, peaceful discourse in the competition of ideas.

All three of these elements are crucial to our country's present and future well-being; they are also interdependent. Modernization goes hand-in- hand with a credible deterrent; both are necessary incentives to persuade the Soviets that it is in their best interest as well as ours to achieve meaningful arms reductions.

So the vote on the MX package concerns far more than one piece of military hardware. It bears directly on our ability to strengthen the peace through arms agreements that make for more security and stability by reducing overall force levels.

The Scowcroft Commission proved that this is not a partisan issue. Its members, drawn from both parties, from several previous administrations, and from some of our best technical and scientific institutions, demonstrated that Americans with widely differing attitudes can cope with a complex, emotional issue, rise above politics, and achieve a workable, bipartisan consensus.

The members of the commission agreed on the need to build and deploy the MX, not as an engine of destruction, but as a safeguard for peace; not as a means to fight a war, but as a deterrent to conflict and an incentive to peaceful negotiation. These are things we all want.

The question now before us is whether or not the Congress will join this consensus, a consensus that can unite us in our common search for ways to protect our country, reduce the level of nuclear weapons and the risk of war. Such a consensus is more than desirable; it is crucial to America's future and to the future of all the civilized values we hold dear and would protect from mass destruction.

If we can consolidate this consensus now, it can be sustained from one administration to the next, from one party to another, and lay the groundwork for steady progress toward arms reduction and a more peaceful and secure world. It is this realization which has caused many members of the Congress, who disagree with this administration on other issues, to make common cause with us on this one. Only last week, Democratic Rep. Les Aspin of Wisconsin explained why the Scowcroft Commission's recommendations deserve support as a tool for peace and arms reductions.

"A core question," he wrote, "is whether you can get the Soviets to negotiate without dangling the MX over their heads. . . . (I) tend to believe we need the MX--not to give the United States the capability to wipe out the Soviet ICBM force, but to turn on a lightbulb in the Kremlin's brain and make it realize that it is in Moscow's interest as well as ours to shift to single-warhead missiles and to agree to a limit on warheads.

"The goal of all this is to prevent nuclear weapons from being used in the first place. The best way to achieve that goal is to create a situation in which neither side has an incentive to use nuclear weapons. That is precisely what the Scowcroft approach does."

The appropriations committees of both House and Senate, on a broad bipartisan basis, have already voted to support this package.

As the full Congress now reaches the eleventh hour, the choice is clear: a vote for the MX is a vote for what all of us--here and among our friends overseas--want for our country and for posterity--peace, security, significant arms reductions and an end to nuclear horror. Toward this noble goal, I pledge to continue to work closely with the Congress in pursuit of a reduction--a build-down--of nuclear arsenals. But, to succeed, I will need its bipartisan support. I cannot think of any single issue where it is more justified, and more vital to the future of mankind.