Tokyo — One year after being elected prime minister, Yasuhiro Nakasone faces the voters in a general election dominated by a single issue: political morality. Such single-issue elections are rare in Japan. Usually governments try to assemble a variety of successes and promises to spread before the electorate, and this time is no exception.
Mr. Nakasone, celebrated for his persuasive oratory and for the ringing clarity of his statements on most issues, would like to emphasize foreign policy , where he is controversial but has solid achievements. His campaign promises will feature tax cuts and administrative reform.
But for all Mr. Nakasone's winning ways, the figure looming largest over the Dec. 18 election is not the prime minister himself but his political ally, former Prime Minister Kakuei Tanaka.
Mr. Tanaka, often referred to as the ''shadow shogun,'' has defied public opinion by refusing to resign his seat in the lower house of the Diet (parliament), despite his conviction on charges of accepting bribes 10 years ago.
Opposition parties were unable to present a resolution calling for Mr. Tanaka's resignation because the ruling Liberal Democratic Party (LDP) refused to schedule the resolution in the Diet.
If put to a vote, the opposition resolution would probably have lost, since the opposition has a combined total of only 207 seats compared to 285 for LDP.
But opinion among the Liberal-Democrats was split, and the party executives, dominated by members of the Tanaka faction, did not want to risk embarrassing abstentions over the matter.
The opposition parties, though frequently quarreling among themselves on other issues, stuck together on the Tanaka issue, holding it to be a matter of political morality. They decided to boycott Diet sessions until the Liberal-Democrats agreed to schedule the resolution.
Mr. Nakasone tried to persuade Mr. Tanaka to resign, but failed. He tried to induce the opposition back to the Diet by promising tax cuts, and failed again.
Mr. Nakasone would have liked to have postponed elections until next year, ideally until the lower house's term expires next June. He argued within his own party that to fight an election when the Tanaka verdict was fresh in voters minds could be politically disastrous for the LDP. Since Mr. Nakasone's own standing within the party will be affected by the outcome of the election, he was obviously speaking from his heart.
But Tanaka himself, and the Tanaka faction which is the largest in the LDP, wanted early elections. Mr. Tanaka is said to calculate that even if the LDP as a whole loses seats, his own faction will either hold its own or gain seats. In the wake of his conviction Oct. 12 (which he is appealing), Mr. Tanaka is said to be convinced that a massive vote for him in his own constituency and a convincing vote for his faction throughout Japan will be the best means to vindicate himself and to ensure his continued kingmaking role in Japanese politics.
Mr. Nakasone was apparently unable to withstand pressure from the Tanaka faction, whose strategy, oddly enough, fitted that of the opposition parties. Thus a compromise was reached: the opposition parties agreed to attend the Diet and allow piled-up legislation to pass, while the government agreed to dissolve the Diet and hold elections Dec. 18.
What will the electorate do?
To many voters, Mr. Tanaka's refusal to resign seems a flagrant defiance of political morality.
In this election, the faction within the party has become an important consideration to many voters. If this mood grows, the LDP could end up with what Mr. Nakasone fears: a sharply reduced majority in the Diet.