The article by Morton Halperin and Alex Whiting {op-ed May 20}, criticizing proposals for a single congressional intelligence committee entirely misses the point. A joint committee would not, as they argue, weaken, but rather would strengthen the ability of Congress to keep an eye on intelligence activities.

The main reason is that it would create a more secure repository in Congress for secret information from the executive branch, whose members have in the past been reluctant at times to inform congressional committees fully about various matters in which they have a legitimate interest.

(Halperin and Whiting, incidentally, are flat wrong in claiming that the CIA withheld needed information about 1984 plans to mine Nicaraguan harbors. In fact, as an April 17, 1984, Washington Post editorial noted, the Senate intelligence committee was informed.)

Much of the executive branch's recalcitrance about sharing sensitive information derives from a legitimate fear that some "leaks" of such materials, whether inadvertent or deliberate, have been attributable to committee members or staff. The Tower Commission, while saying Congress may have been disproportionately blamed for leaks, concluded that the large number of staff and members reviewing covert activities "provides cause for concern and a convenient excuse for Presidents to avoid Congressional consultation." Therefore, it recommended congressional consideration of a joint committee with restricted staff.

While it is true that some in the executive branch are masters of the leak, Capitol Hill is in fact notorious for its failure to establish even a minimal security system. Some of this aura rubs off on the intelligence committees, even though they are generally more rigorous.

Moreover, intelligence agencies distrust Congress -- and other executive branch agencies -- more than their own employees who are polygraphed. No members or congressional staff are subject to polygraph either as a screening process or during a leak investigation; indeed, it is highly unlikely that they will ever be punished or even investigated for suspected leaks. Members automatically are given security clearances without even a background investigation.

Some suspicion of Congress traces to the very milieu of the politician. Elected officials may prosper or perish according to the extent and friendliness of their press contacts and the newsworthiness of their comments. Interestingly, intelligence committee assignments have become highly coveted, in part because of the visibility and prestige recently accorded to committee members. In contrast with lifetime intelligence professionals, knowledge and habits of strict security have not and usually cannot be deeply ingrained in the politician.

Because of this, their constant contact with the press, their often strongly held political beliefs and their frequent involvement in impassioned public debate, it is only natural to expect that politicians will be unusually prone to accidental and even intentional disclosures of classified information. Agencies often are reluctant to share innocuous information for fear that publicity-seeking members or their free-wheeling staff will later abuse that precedent to facilitate hasty, sensational accusations or to support unreasonable and politically motivated demands.

Some legislators and staff, like some persons within the executive branch, tend to dismiss security concerns as the "Mickey Mouse" preoccupation of mindless bureaucrats. The need to protect intelligence sources and methods sometimes is treated lightly. And a tendency to dismiss many disclosures as not involving "national security" per se is becoming nearly universal, even when such leaks deeply embarrass the United States or its allies and curtail our policy options.

Within Congress at large, there is a widespread and often naive suspicion of both secrecy and covert actions, as well as a distrust of the intelligence agencies. The most significant of covert actions, particularly those involving paramilitary forces or ideological opposition to the "Reagan Doctrine," have become highly politicized, with strong pressure to align along party positions. In these circumstances, it is small wonder that the administration has become convinced that controversial programs will be leaked.

Currently, the House Intelligence Committee has 17 members and 20 staff. The Senate has 15 members and 38 staff. Does efficient oversight require 32 (plus 4 ex officio) members and 58 staff? One could argue persuasively that a streamlined single committee as we have proposed with H.J. Res. 48 could operate far more efficiently, with much less wasteful duplication of effort, less catering to members' individual and political needs, and perhaps more creative and serious initiatives.

We might even transcend the mentality of chasing headlines and get down to the real business of oversight -- problems in intelligence collection and analysis affecting basic, long-term national security interests, and the painstaking consideration of fundamental reforms.Rep. Hyde (R-Ill.) is the ranking Republican on the House Intelligence Committee. Rep. Lungren (R-Calif.) is a member of the committee.