A transition to what? That is the question facing the Communist Party leadership here, the Soviet people, and - to varying degrees - the rest of the world as the Soviet Union replaces Yuri Andropov.
At time of writing Sunday, the front-runner to take over from Andropov, who died Thursday, appeared to be Konstantin U. Chernenko. Selection of the 72 -year-old Chernenko, a protege of former Soviet leader Leonid Brezhnev, would represent a decision in favor of caution.
It would postpone a little longer the switch to a younger generation of leaders that this country must eventually face. It would signal a reluctance to give power to a younger man who might have the time and energy needed to come to grips with the Communist system's deep political, economic, and social problems. It would deeply disappoint those Soviets who favor reform.
But a Chernenko shoo-in was by no means certain Sunday night. Other leading contenders were said to be Grigory V. Romanov, 61, and Mikhail S. Gorbachev, 52. They are the only men who combine membership on the ruling, 12-member Communist Party Politburo with a post on the Secretariat of the Central Committee - seemingly requisite for selection as the general secretary of the party and leader of the Soviet state.
A man like Gorbachev is at the other end of the political spectrum from Chernenko. He is one of the rising generation of Soviet leaders whose higher education was uninterrupted by war, men who are primarily technocrats rather than political operatives.
Eventually, the Soviet Union must inevitably make such a generational change. The average age of Politburo members is now 67 - and it is that young only because Mr. Andropov managed to appoint two younger men during his 15-month rule.
On the other hand, a decision to select Chernenko would signal clearly that the Soviet Communist Party is still controlled by people like him - veteran party loyalists whose world view has been shaped by World War II.
Whoever is chosen, and despite the undoubted economic and military power of the country he will lead, the next Soviet leader is likely to be able to effect far less change than he might want. For one thing, he will have to move cautiously at first to consolidate his own grip on the party apparatus. For another, there are a variety of factors that will constrain him.
For example, any abrupt change in foreign policy is unlikely. That policy, for much of the past quarter-century, has been stewarded by Foreign Minister Andrei A. Gromyko. He will likely continue in the post.
Moreover, the foreign-policy impasse now prevailing between the Soviet Union and the West is based on concrete issues - such as the nuclear and conventional military balance in Europe - that transcend the personality of either the Soviet or American leader. Quick resolution of these issues is unlikely, despite the optimistic statements of some Western government figures.
A pragmatic leader might quietly abandon the hard-line stance of Andropov and become somewhat more conciliatory, so long as he can save political face in the process. But so long as the new leader is consolidating his power - a process that can take years - few radical foreign-policy swerves are expected.
And it is very likely that efforts at reforming the rigidly centralized Soviet economy will continue. Starting with Joseph Stalin in the 1920s, successive Soviet leaders have been wrestling with the problem of modernizing the economy. But it has been a fitful process.
The Soviet Union now leads the world in production of steel, oil, coal, and some other categories of heavy manufacturing. But it lags far behind in high technology, services, and the production of consumer goods.
Some Soviet officials are painfully aware of these shortcomings. Andropov launched some limited experiments at giving more economic decisionmaking power to those who run the country's 36,000 industrial enterprises, rather than central planners in Moscow. During the last days of Andropov's leadership, the party announced expansion of these experiments into some service enterprises.
Still, the experiments were limited, both in the numbers of factories and the geographic areas involved. Western analysts say they will make little difference in the overall Soviet economic picture.
A Central Committee member says they were intended only as experiments, to run for a year or more, to give planners data by which to evaluate them. Then, and only then, he says, will the government expand them.
Another Central Committee member says the government is looking for ways ''to tie wages more closely to the quality of the work'' - hardly a radical notion, but one that nevertheless sparks some controversy here.
Presumably, the experimentation will continue, and it might even be expanded if someone like Gorbachev takes over. On the other hand, a man like Chernenko might be more inclined to let the current experiments play themselves out and then quietly scuttle them.
He would then be faced with the same fundamental problem: an economy without much dynamism or innovation. And Western analysts say no Soviet leader can ignore that situation for long.
The reason some Kremlin-watchers were giving Chernenko the edge over his rivals at time of writing rested largely on the basis of his appointment as head of the honorary funeral commission. Twice in the past the head of the funeral commission has been named the next party leader.
But other analysts warned that that might not necessarily prove true this time. When Leonid Brezhnev died in 1982, it is believed that the ruling Politburo chose Andropov as his successor. The larger Central Committee - with about 300 members - apparently was convened only to give pro forma approval to the selection. This time, these analysts believe, the Central Committee may play a much larger role in the process. It was expected to meet Feb. 13.
In addition, at least one well-placed Soviet source says that during this transition - as during the last - the Soviet military will play a pivotal role. And the military's preference is unknown.