George Bush has taken a somewhat cautious approach toward the Soviet Union that lacks the visceral distaste that Ronald Reagan had for the "evil empire" at the outset of his presidency.

Together, the incoming and outgoing U.S. presidents will sit down for lunch with the Soviet leader in New York on Wednesday and solicit a commitment from him to maintain a four-part agenda for superpower dialogue that gives high priority to human rights and arms control.Still, Bush said recently that he would not try to put his own spin on the session. "In terms of specificity, in terms of my committing a brand new administration to specifics in arms control or anything else, I'm not going to do that," he said.

His general approach to Moscow and the innovative Gorbachev is one of caution.

"Remember, the Cold War is not over," Bush told a San Francisco audience last July.

"The leadership of the Soviet Union is changing, but old ambitions die hard," he said in October. "Systems die hard. The leaves may be falling, but the trees are fundamentally the same. As much as we welcome the change in the Soviet Union, now is not the time to abandon realism about what makes the Soviet Union move."

Bush was on the campaign trail then. Presidents have a habit of changing their rhetoric as well as their policies once in office.

Bush, who prides himself on his foreign policy experience, has traveled to 72 countries and been U.S. ambassador to the United Nations and to China, and director of the Central Intelligence Agency. Those jobs _ and the vice presidency _ give Bush some insights into how the Soviets operate.

How much a role he played in the Reagan administration's gradual shift from hostility toward reconciliation remains an open question. His own record and statements indicate a generally middle-of-the-road stance.

At least one point seems clear. Bush, like Reagan, is heartily in favor of a further U.S. military buildup. "Those who want to abandon the policy of peace through strength in the hopes of self-induced Soviet restraint are dead wrong," he said in October.

The question is whether Bush will have to give ground while trying to cope with the U.S. deficit and other economic problems.

Former Sen. John Tower, considered the front-runner for defense secretary in the Bush administration, championed Reagan's defense buildup in Congress. Brent Scowcroft, Bush's choice for national security adviser, has suggested cuts of at least $300 billion from the Reagan administration's military spending plan for 1990-1994.

How Bush will deal with the deficit and military buildup still is uncertain. Scowcroft, who was national security adviser to Gerald Ford, is an experienced strategist who is inclined to move slowly in working out agreements with Moscow.

On the other hand, Bush's choice for secretary of state, James A. Baker III, has little experience in foreign policy and has never been to the Soviet Union. Like Bush he has a reputation for being a conservative but not particularly ideological.

Still on the negotiating table as Bush prepares to take office is a prospective treaty to reduce the two powers' armories of globe-girdling missiles, bombers and submarines by 30 percent to 50 percent.

Also on Bush's agenda: chemical and conventional weapons.

Bush voted twice in 1983 to break Senate ties on bills authorizing development of new chemical weapons. In the campaign, however, he called for a ban and claimed that it was "my issue" since he took a draft treaty banning such weapons to the Geneva disarmament conference in 1984.

On the campaign trail, Bush also advocated cuts in non-nuclear forces in Europe.

On Reagan's prized Strategic Defense Initiative, popularly known as "Star Wars," Bush pledged to "research and deploy a missile defense system, as soon as it's practical."

The hook is "practical." Many of the program's critics doubt it will ever be sufficiently airtight to justify the enormous cost of going ahead.