President Carter says he doesn't "panic in a crisis." But that's not the problem. The problem is that he panics without a crisis.

Or, to be more specific, the problem is the wobbly way he handles pseudocrises, such as the needless furor over Russian soldiers in Cuba.

Fortunately, Carter can generally be counted on to keep his head in a real showdown, but it was his early over-reaction that dramatized and magnified the non-threatening presence of the troops into a dangerous confrontation with the Soviet Union.

Although the president has now acted prudently and responsibly in trying to douse the flames, there would not have been a four-alarm fire if the administration had not kindled it to begin with.

In the process, the president has thoughtlessly jeopardized the prospects for SALT II, the arms agreement in which the whole world has a stake. In the words of The Economist, his performance "adds a new question mark to the public mood of doubt about Mr. Carter's capacity to handle the affairs of the United States."

The president seems to have a weakness for melodrama; he gets excited over relatively inconsequential happenings, such as the defection of a Russian dancer. Only a couple of weeks ago, the White House and State Department turned the event into an international incident by engaging in a running battle uith Soviet officials over the expressed desire of the dancer's wife to return to Russia. It hardly deserved to become a television spectacular.

Also only a few weeks ago, Carter let Andrew Young's talk with a Palestine Liberation Organization agent be elevated from a diplomatic indiscretion to international drama. What could have been disposed of or minimized through conventional quiet diplomacy ended with the controversial departure of the U.N. ambassador, with damaging consequences for the president and Israel.

Carter also inflicted damage on himself by his sudden impulse to purge the Cabinet. After repeatedly being told by the president that his Cabinet was "superb" and that he was proud of keeping it intact, the public can hardly be blamed for being bewildered over the clean-out. To many, it looked like political panic, inspired by the president's drop to a record low in the opinion polls.

Carter's partiality for crises is nothing new. He began his administration with what he called the "energy crisis." His campaign to lick it was to be the "moral equivalent of war." It later became known by its acronym: MEOW.

In campaigning for the presidency, Carter warned against the "inordinate fear of communism," but many of his troubles in office can be traced to his futile efforts to appease and mollify his Cold War critics, most of whom are not appeasable, as shown by their dour reaction to his restrained television speech on Cuba.

One reason the public perceives Carter as erratic and vacillating is his habit of denouncing Moscow one day and promoting detente and the U.S.-Soviet arms-limitation agreement the next. In the present Cuban fiasco, he started with tough talk and belatedly ended with a conciliatory speech.

There is a pattern to this. He pleased the right wing by refusing to recognize Cuba until Fidel Castro's troops are withdrawn from Angola, but he also came to agree with Andy Young that the Cuban presence in Angola was a "stabilizing" factor, as it obviously has been.

In Iran, Carter at first wept overboard for the shah, whom he embraced for his "great leadership" and for "the respect and the admiration and love which your people give to you." Again, however, when the chips were down, Carter had some saving second thoughts. He resisted the temptation to intervene in a last-minute effort to save the shah. He did, it is true, order a carrier task force to the Persian Gulf, but he later countermanded it.

It's a pity that Carter, in attempts to impress the nation's hardliners, has compromised his admirable record as a peacemaker. Yet, if he manages to salvage SALT, he can do much to restore his peacekeeping reputation.

After all, he is still the first president since Herbert Hoover who can claim that not a single American soldier has died in battle during his tenure. There could hardly be a better campaign claim for no American president has ever been defeated running on a peace platform. That means, however, being for peace, period -- not for peace, but . . .