FRANKLY, WE THOUGHT we'd seen the end of the Korean influence-pedding inquiry last week when the House ethics committee summed up what wrongdoing it had found in a year and its special prosecutor, Leon Jaworski, announced he'd gone as far as he could without Kim Dong Jo. This week the inquiry suddenly revived, however, with word that Mr. Kim, the former ambassador in Washington who has been accused of bribing as many as 10 congressmen, will be responding to the committee's queries after all. His cooperation is critical: Congressmen on the take from rice dealer Tongsun Park could deny they were dealing with a known foreign agent, but this is not a claim that anyone on the take from Ambassador Kim can sustain. Taking something "of any kind, whatever" from a foreign official violates a constitutional ban; it is not a crime for which a congressman can be prosecuted, but it is something for which a member could properly be punished by the House.

The key apparently is that the Koreans, after rejecting a final personal appeal by House Speaker Thomas P. O'Neill to receive two special emissaries on the Kim matter, felt obligated to do something to remove the bitter taste their stonewalling had left in American mouths. That Mr. Jaworski, Seoul's nemesis, had meanwhile withdrawn from the inquiry and that, notwithstanding the scandal, Congress had voted military aid perhaps made it easier for Seoul to bend without seeming to lose face by buckling under American pressure. The State Department encouraged a gesture of reasonableness to sweeten the future atmosphere in which Washington will regard Korea. Ethics committee chairman John J. Flynt Jr. (D-Ga) assented, seemingly disposed for personal reasons to try to show that he could extract information from the Koreans that his disaffected special counsel, Mr. Jaworski, could not.

Skepticism is very much in order, nonetheless. Mr. Flynt, with the State Department quietly seconding him, suggests that the Koreans have offered assurances that the Kim answers will be accurate and substantial: Names will be named. Hmm. Procedurally, the terms - an exchange of letters - under which the House has agreed to question Ambassador Kim are those Mr. Jaworski earlier rejected. There is no requirement that, at least at some later point in the process, the testimony be taken under some form of oath; and there is no provision for cross-examination, though there is a prospect that "clarifying" questions can be asked. The danger is that any material provided by Mr. Kim will be merely a smear, or unusable in a subsequent House disciplinary proceeding.

The tough decisions now are Korea's to make. Having gotten through the American political year bruised but upright, Seoul might well have concluded that its stonewalling had paid off. If it is in fact still prepared to consider good-faith cooperation with the House inquiry, that is greatly to its credit.If, on the other hand, the Koreans are playing games, the cost will be heavy indeed. It will be painfull to just about everybody concerned if Ambassador Kim helps verify even some of the allegations that have been made against him. But it will be a wise investment in the candor and trust that good friends and allies owe each other.