Sublimely unaware of the rich vein to be mined on the defense issue, Ronald Reagan's political high command overruled his national security advisers last week and again vetoed an attack on this Achilles' heel of President Carter's four-year record as commander-in-chief. a

"Put it down to overcaution because of the warmonger nonsense," one disappointed Reagan defense consultant told us. "The politicians around the governor are afraid it will only fuel the charge that he wants an arms race." A better explanation: campaign anemia.

The insiders' struggle over putting the defense issue on the firing line against Carter is by no means over. As polling evidence piles up showing that Carter's warmonger campaign is hitting home (despite disgust among some voters), Reagan has this choice: pretend it isn't happening or counterattack. v

Having failed last week to bring Reagan out of the trenches for counterattack, his defense advisers are now putting final touches on a devastating critique of Carter's management of the nation's defenses while the Soviet Union rolls up one country after another in Africa, Asia and the Middle East. The heart of this critique is that Carter has deceived the American people about the true balance of military power -- that, in the phrase of one Reagan defense consultant, he has engaged in "perfidy on the defense commitment."

An April 8 memorandum to Secretary of Defense Harold Brown from Assistant Secretary John R. Quetsch, the Pentagon comptroller, lays the foundation for Reagan's line of attack. Reporting to Brown that the White House wants to "show a 3.1 percent real growth" in defense spending for 1981, Quetsch said that "to accomplish this requires a further lowering of 1980 outlays of $83 million." Translated, that puts Carter on record as ordering a reduction in 1980 defense spending already voted by Congress so as to make 1981 spending appear that much greater. Quetsch continued: "Alternatively, we would have to claim inflation of only 8.91 percent rather than 9.05 percent in order to arrive at the 3.1 percent real growth."

Quetsch's transmittal of this extraordinary message to Brown followed by four days a confidential memorandum to Carter from Budget Director James T. McIntyre Jr. Since inflation was higher than expected, McIntyre reported, the new costs of weapons "will be absorbed" by the Pentagon, reducing Carter's public pledge from a 5 percent real growth to 4 percent real growth for the next five years.

Armed with these and similar internal administration revelations, Reagan's defense advisers see them as bedrock for a multi-pronged attack on the candidate who campaigned in 1976 on a pledge to cut defense spending by $5 billion to $7 billion.

The political message that these advisers want to send voters is that war cannot be prevented by weakness, but only by strength. "It is simply not acceptable that a president who has allowed our military strength to be weakened compared to our adversary can call Reagan a warmonger for trying to correct the balance," a senior aide told us.

Reagan's own imprecision has played into Carter's hands, but this defense team believes his inept and careless handling of the SALT II treaty is salvageable. Instead of treating SALT II as a worthless scrap of paper, Reagan is being pressed to make clear that his intent is to keep negotiating a better agreement, using the stick of expanding U.S. military strength to induce Soviet cooperation. This would parallel U.S. bargaining leading up to SALT I, when the threat of a superior anti-ballistic missile system was used to induce Soviet Cooperation.

The non-warmonger Washington Post and New York Times are now warning in front-page displays about the dangerously weakened state of America's once-supreme military might. So Reagan's defense team is telling him that a scrupulously honest, objective attack on Carter's defense shenanigans could score heavily with voters.

Reagan's political aides, exhibiting their customary blandness, still resist. If they continue, they burden Reagan with the worst of two worlds; no serious riposte to the warmongers brand burned on him by Carter; no exploitation of Carter's "perfidy" as commander-in-chief.