If the rest of the country is excited about the visit of Soviet leader Mikhail Gorbachev, the residents of Washington, D.C., are ecstatic. After all, he is visiting our city, walking along our streets, tying up our traffic. Indeed, the Soviet leader is doing all of this at a cost of probably millions -- which Mayor Marion Barry hopes the federal government will pick up.

Of course, no price can be put on the opportunity for furthering world peace that Gorbachev's visit brings. And most Washingtonians are happy despite blocked streets and dizzying detours; after all, inconvenience, even an occasional snarling cop, beats the possibility of world annihilation.

And on every corner there's an opinion.

For one black man who declined to have his name used and who said he spent a long time in the Soviet Union, the signing of the nuclear missile treaty "is a good thing." But he surveyed with skepticism the human rights protesters brandishing signs and bumper-to-bumper limousines bearing dignitaries. Then he shook a frail finger and issued a warning:

"Constant vigilance should be the top priority of the West and it should never be forgotten that, owing to the vastness of Soviet territory and the leaders' long-term goal, preparation may have already been worked out for both inspection and cheating to go on simultaneously."

But Allison Blakely, a Howard University professor of Russian history, while sharing some of those concerns, feels that historic foes signing a pact to destroy 2,611 missiles is truly a radical step. "This really new kind of relationship is just unfolding," he said. "Much will depend on how well the present administration exploits the new constructive momentum and on whether the next president ensures that the U.S. maintains the initiative in the relations between the two powers."

From my side of the street, the pact on intermediate-range missiles is an important first step in the de-escalation of tensions between the superpowers. Of course, agreements must also be reached on long-range strategic missiles, and, lest the door to an older style of warfare be opened to the superpowers, conventional weapons.

Clearly, Reagan and Gorbachev are meeting and reaching accords to reduce the size of their countries' nuclear stockpiles for a number of reasons. Ironically, personal power for each man has played a major role in his efforts to seek peace.

Gorbachev needed this Washington triumph in order to improve the austere economic plight of the discontented Soviet people, lessen pressure on the leadership and solidify his power.

While President Reagan has won many domestic victories, he is a lame duck president whose chief marks on the international front have been failures. Reducing nuclear arms remains the ultimate victory for any modern president and he is willing to buck his right-wing cohorts to write himself a favorable record in history. Unlike Richard Nixon, who might have left his presidency with the crowning achievement that he opened the door to China had he not become mired in Watergate, Reagan has survived the Iran-contra affair to write a new chapter in Soviet-American relations.

Indeed, there is a larger irony that had a liberal president conducted similar negotiations, as Jimmy Carter did in SALT II, there would be charges of "sellout" and "puppet of the Russian government" from several quarters, not only the extreme right wing.

Of course, despite this week's hyperbole and dangers, challenges and ceremony, peace is not yet in the bank. The missile treaty still has to go to the Senate for ratification and the hope is that the Senate will act on it favorably. But there is another hope as well -- that while being duly vigilant, the senators don't play extensive politics because what is at stake is much more than has ever been at stake before -- the world's peace and security.