Talking to people about the Iran crisis, you find, along with the frustration and rawness, a growing readiness to question Jimmy Carter's categorical rejection of a military option.

There are a couple of levels of concern. The first is evoked by Ronald Reagan suggestion that, through circumstances have changed, perhaps a show of force right after Nov. 4 would have freed the hostages. This is easy for Reagan and others to say: they do not have to deliver. But people I talk to are a good deal less willing now to dismiss this possibility. They discount that a vigorous threat or an actual rescue attempt might have jeopardized the hostages' lives. Consent grows for the proposition that because everyone knows the Soviets would answer an embassy seizure with tanks by teatime, their embassy would not be seized.

There is a second, broader level of concern: that military passivity, besides tempting other would-be hostage takers, contributes to a perception of America by friends and foes alike as a country shrinking from its responsibilities as a world power. The seizure of hostages (including the American ambassador) in Colombia and the Soviet invasion of Afghanistan are increasingly seen as acts whose perpetrators have paused if Jimmy Carter had responded more firmly in Tehran.

I don't find these particular connections convincing. But a lot of people who might have brushed off any hard cause-and-effect linkage a few months ago now seem readier to accept (as I would) that the calculations of would-be terrorists and aggressors are affected, marginally at least, by their readings of what the traffic will bear.

At one point, Jimmy Carter appeared to be picking up signals like these. "When something happens and it endangers our national security, or when something happens that threatens our stature in the world, or when American people are endangered by the actions of a foreign country or just 40 sailors on the Mayaguez," Jimmy Carter in the second debate with Gerald Ford in 1976, "we have to move aggressively and quickly to rescue them." He was referring to President Ford's dispatch of an armed force, from which 41 Americans were lost, to rescue the (40) crewman on a merchant ship that had been seized off Cambodia.

The other day, however, Carter took another tack, one he has taken through the Iran crisis and, for that matter, through his whole presidency. In his interview with Meg Greenfield, he needled Ford for losing More Americans than he saved in the Mayaguez incident and he solicited appreciation for passing up the "temptation" of using military action to win popularity. He said he had forsworn force "altogether" in Iran and Afghanistan, and boasted that he has lost no American lives in combat -- "the first time in 53 years that that has happened."

The Carter we see is the Carter we get. At this point in his administration, it is idle to expect either a policy change of Iran -- the clock can't be turned back to Nov. 4, anyway -- or a personality change. It is, by the way, precisely this feeling that Carter's responses are rooted in event-proof basic values and syndromes that makes even many of his supporters gulp. Yet, obvious as they may seem to some, the assumption lying behind his remarks on the use of force are worth noting, especially since he does not show public signs of having examined them.

The short-term arithmetic does count: 41 (military men) dead, 40 civilians) saved. But the long-term mathematics also counts: the effect on other decisions made at other places and times.

Using force may be an easy political "temptation," but it can also be a hard political duty. Denying oneself what Carter calls "transient" popularity -- as distinguished, presumably, from the nation's deep gratitude -- may or may not produce the right policy.

To forswear force publicly in a crisis may convey to the adversary an element of good will useful in negotiation, or it may simply convey flabbiness. Carter seems not to concede there's an argument, at least in the area of tactics.

A president who boasts he has not lost a soldier in combat is making a statement about his religious convictions and his fidelity to the anti-Vietnam consitituency and mentality that helped elect him. But he is also betraying a disregard for the chance that others may read his words as an invitation to steal the United States blind.

It was silly for so many Americans to greet Mayaguez, as they did, as an instant fix of the pride and position lost in the Vietnam war. It is no less silly for Jimmy Carter to expect personal virtue to produce national reward.