For five years Jesse Helms has been abusing the reputation of the Senate by putting "holds" on Reagan administration national security nominees. On occasion the muscle-flexing has been, at least in retrospect, bizarre. One nominee whom Mr. Helms opposed in 1981 as possibly not quite tough enough toward the Soviet Union was Caspar Weinberger, then best known as a budget-cutter. "The national crisis which America faces is a crisis of sheer survival," Mr. Helms said then, "and for survival, Mr. Weinberger's dedication to efficiency, frugality and sound management simply are not enough."

Most other examples have been more serious. Mr. Helms, now second-ranking Republican on the Senate Foreign Relations Committee, has been able to squeeze concessions from nominees and stall or kill nominations in sensitive areas of policy -- Latin America, southern Africa, arms control. In none of these instances has he quite had the taste to take on President Reagan directly, nor has the president taken on Mr. Helms. Instead the senator has taken refuge in the fiction that the disputed nominations were pushed past an unwitting president by aides -- White House staff members, his secretaries of state -- who unaccountably failed to reflect his views. He has been trying, he suggests by this device, not to alter policy but to save it.

In the most recent example of the game, Mr. Helms and several other senators have been protesting what they call an "ideological purge" of conservatives from the State Department by Secretary George Shultz. They have insisted that one assistant secretary -- James L. Malone, in charge of oceans and international environmental and scientific affairs -- and five ambassadors threatened with loss of their jobs be kept on or find other work. They announced they were putting holds on 29 other diplomatic nominations, including several of consequence.

Last week the administration said it would find jobs for the six. By Thursday, when it had found jobs for three, Mr. Helms agreed to lift 14 of the 29 holds in turn, and then sent a letter to say he would add a fifteenth "provided I receive assurance from (White House chief of staff) Don Regan and Secretary Shultz that Jim Malone will be nominated for ambassador to either Panama or Belize."

The deal was not struck. Some other senators objected, as did the State Department. Congress went home with the nominations still on the shelf. Majority Leader Bob Dole lamented afterward that there had been "no winners or losers except those poor guys stuck on the calendar." Not so. The Senate also lost, in stature. Mr. Helms made it look simultaneously ineffectual and shabby. When they reconvene, his fellow senators should free the State Department 29.