The word from the White House is that President Reagan's State of the Union message to Congress this week will be light on creative legislation: time is running out. It will deal sternly with such unfinished foreign affairs as aid for the Nicaraguan contras and ratification of the intermediate-range nuclear weapons treaty. It will be generous in its accounting of the achievements of the Reagan presidency; history must be served.

It will, in short, be vintage Reagan -- upbeat beyond the bounds of credulity, with scant regard for the grim choices he will leave behind. If the inside dopesters have the right reading, the president in his final year in office will put no part of his favorable approval ratings at risk. He won't tell the American people what they suspect but don't want to hear: that the ''Union'' is in an increasingly poor way to fulfill the role that Reagan himself would have it play in an unresponsive world.

True, it would be a lot to ask. Gerald Ford is the only president who ever saw cause to say flat out that ''the state of the union is not good.'' And not even Ronald Reagan, for all his irrepressible optimism, is likely this week to match Franklin D. Roosevelt's famous ''Four Freedoms'' vision in 1941.

A little less than a year before the United States got into World War II, FDR was holding out the real prospect -- ''everywhere in the world'' -- of freedom of speech and religion and freedom from ''want'' and ''fear.'' By the last, he meant worldwide disarmament to a point ''that no nation will be in a position to commit an act of physical aggression against any neighbor -- anywhere in the world.''

Reagan, then, will be breaking no new ground if he lets his rhetoric soar. Still, an election year is a perfect time, and Reagan is in a perfect position to turn off the dream machine (a nuclear-free world; ''freedom fighting,'' anytime, anywhere; guns and butter -- and a balanced budget, by constitutional command) that has served him so well for so long. He would have no political fortunes of his own to lose (and a lasting legacy to gain) if he should seize the opportunity of his final year. He could put his fabled communications skills to the service of greater public recognition of home truths and harsh realities.

For this, it would not be necessary for the president to abandon the true beliefs he brought to the Oval Office seven years ago. He need only try to reconcile them with his own, hard-earned, firsthand experience. He need not even lay claim to sure answers. It would be enough for him to identify the right questions that the presidential candidates ought to be asking each other and the press and public asking the candidates.

I have in mind the kinds of overarching questions that Henry Kissinger would call ''conceptual,'' such as how to weigh American roles and missions around the world against resources, across the board. Or what counts the most, military or economic power? And where do you strike a balance, when we have just progressed through the biggest peacetime military buildup in history and now find ourselves on the edge of insolvency?

These are not free choices. They are being forced on us by trends and events beyond our control: a Soviet government (and a communist bloc) with a new look; the early signs of growing regional cohesion and/or emerging power centers in Western Europe, the Far East (China and Japan) and Latin America. All pose challenges of one sort or another; all work to diminish the relative economic as well as military weight in the world, not just of the United States but of the Soviet Union as well.

And all cry out for at least a decent effort to address national security problems in the round and in a time frame longer than the life of a Congress or a presidency. Not even Kissinger would argue that this is easy. Drawing in his memoirs on eight years at the center of policy-making, he conceded that American pragmatism ''produces a penchant for examining issues separately, to solve problems on their merits without a sense of time or context of the seamless web of reality.'' Americans of whatever ideological persuasion shy away from ''permanent exertion,'' he wrote.

Now that may be heavy stuff for the hustings, or for a State of the Union message. But not all that heavy if the polls and other recent studies are right about the American public's state of mind: confused, frustrated, suspicious of past answers, ambivalent about the use of power, yearning to pay the costs. What this suggests is that there may be a larger constituency than you might suppose for consistency, continuity and above all straight talk from those who conduct our affairs. A popular two-term president in his final year is uniquely placed to meet that need.