THE INDICATIONS are the onset of Ronald Reagan's presidency has concentrated the mind of Iran in a way that Jimmy Carter's own approach to negotiations never did. Whether this bears fruit in an agreement on the terms on which Iran will end its illegal incarceration of the American Embassy staff may not be known until the clock ticks down on Friday. At the least, however, it makes plain that it is not merely the arrogance of the Iranians and the disarray among them that have prolonged the crisis. Some Iranians must also have thought it was perfectly safe fo them to spin out the crisis and that, by spinning it out, they might get better terms. These are the assumptions one hopes are fading in Tehran now.

At any given moment the actual state of play of negotiations is cloudy, even perhaps if you are on the inside. What is evident, though, is that talks have gone beyond the substantive terms into the implementing arrangements that must be made on account of the massive distrust the two sides feel for each other. Realistically speaking, one can understand why this is so. It is, nevertheless, exceedingly distasteful to see the United States playing this game. Americans did not create this crisis. Iranians did, by committing a breach of international obligation and custom for which they have not made amends to this day. They are the untrustworthy ones and, if fairness were the standard, the entire burden of demonstrating good faith in carrying out terms would be on them. That the United States must labor under a similar premise of unreliability is no less a gross imposition for being a requirement of the bargaining process.

Senate Majority Leader Howard Baker, on Sunday, offered the Carter administration "honor" both for terms it is attempting to negotiate and for not simply dumping the problem onto the incoming Reagan team. He made the fair point, one the administration has also made, that the funds the United States contemplates transferring to Iran do not amount to "ransom" since the money was Iran's in the first place. At the same time, he defended Mr. Reagan's refusal to issue the Carter administration a "blank check" to pass on to Iran, suggesting that Mr. Carter's chances of reclaiming the hostages might improve "if the Iranians are uncertain about what position President-elect Reagan will take." That sounds pretty sensible to us. Implicitly it helps keep Mr. Carter honest during the countdown and explicitly it tightens the screws on Iran to come to terms at once.