Washington — The No. 1 topic of interest and concern in Washington is: Will the Soviets seek to take advantage of the transition period by invading Poland? But then comes the related question, one that eludes any precise answer: How much cooperation would there be between the President and President-elect should the Soviets make this move -- or, for that matter, should any other global crisis occur before Ronald Reagan's inauguration on Jan. 20?
The answers out of the Carter White House are clear on one point: "There can be only one commander in chief -- the President," say a top aide to Jimmy Carter. "But if there is some adventurism in the world by some foreign nation that thinks we would be handcuffed at this time, I can envision Reagan becoming a consultant.
"I can even imagine the two of them coming out of the White House and issuing a statement, the President stating what he was going to do and Reagan expressing his support."
From the Reagan camp came this observation by a key aide: "We'd have to take a hands-off position in terms of advising what the US action should be. That's up to the President. That's in accordance with the Constitution. But I would expect Reagan to be very cooperative -- very supportive."
The question of how Carter and Reagan would act if a crisis occurred is most relevant. History records how hard President Buchanan worked -- to no avail -- to try to prevail on his successor, Abraham Lincoln, to involve him in a Buchanan compromise plan aimed at trying to keep the union together.
And Herbert Hoover got nowhere with Franklin D. Roosevelt during the transition when Hoover sought to gain FDR's support for proposals he was pushing , aimed at dealing with the depression.
Mr. Reagan, of course, has already met with Mr. Carter and spent much of his time in listening to the President provide details on international problems. Reagan came out of the session looking quite sober.
The President-elect also has made it very clear to Soviet leaders that invasion of Poland would seriously impair US-Soviet, relations, thus echoing the President's warnings.
However, the Reagan aide emphasized that, should a crisis of this nature occur, Mr. Reagan will be very scrupulous about staying out of any involvement that would look like he was in the decisionmaking process: "It would be on Carter's watch, not ours," he said.
Both Carter and Reagan aides say that the personal relationship between the two is reasonably good now. "They've pretty much buried the hatchet," one Reagan associate says. And a White House staffer makes a similar evaluation of how the two leaders now look upon one another.
Washington observers recall the Truman-Eisenhower transition. The two simply weren't speaking.