When my colleague and friend Sen. Fritz Hollings (D-S.C.) speaks out on key national security issues, people usually take notice. When Sen. Hollings speaks out on the meaning of the ABM Treaty {"Fighting Over the ABM Treaty," op-ed, Sept. 29}, people should take special notice. As he points out in his article, Sen. Hollings participated in the ABM ratification debate in 1972 and voted for the treaty.

I must confess, however, that I am puzzled as to which interpretation the senator from South Carolina is advocating. In his article, Sen. Hollings states that the treaty "is a remarkably straightforward document -- a model of precise, meticulously crafted language" and argues that the "explicit, common-sense text" lends itself to one, and only one, reading -- that is, the administration's reinterpretation permitting the unrestricted development and testing of all ABM systems and components based on "other physical principles" (i.e., so-called exotic ABMs).

Sen. Hollings dismisses as politically motivated the traditional interpretation of the treaty, which bans the development and testing of all mobile (but not fixed, land-based) exotic ABMs. On the same grounds, he rejects the "anything goes" interpretation advanced by some Defense Department officials that even the deployment of exotic ABMs is permitted by the treaty.

It is interesting to note, therefore, that just a few months ago Sen. Hollings was waging a campaign in support of the same Defense Department interpretation he now rejects. In a March 17, 1987, letter to President Reagan, Sen. Hollings concluded that based on his personal involvement in the 1972 debate and the "considerable time" he spent reviewing the treaty negotiating record submitted to the Senate last year:

"Research and development of futuristic technologies were not restricted nor was deployment except for the requirement that prior thereto there be consultation between the Soviets and the United States. Obviously, the one party determined to deploy would learn the cost from the other party opposing deployment at the time of consultation. But even deployment itself was not prohibited."

On March 26, the senator testified before a joint hearing of the Senate Foreign Relations and Judiciary committees that one can reasonably contend that the treaty provides "a right to deploy" Strategic Defense Initiative systems subject only to informing the Soviets of our plans.

I am gratified that Sen. Hollings now believes that this "anything goes" interpretation is the contrived product of "militant conservatives . . . hell-bent on immediate deployment of an SDI system." Given the senator's recent shift, perhaps he still has an open mind as to the correct interpretation.

Indeed, I hope he will continue to review the arguments in support of the traditional interpretation and reflect further on the deficiencies of the administration's reinterpretation. In time, I hope he might make yet another switch and join the overwhelming majority of former ABM negotiators, senators, House members and Nixon, Ford and Carter administration officials (including six former secretaries of defense) who stand firmly for the original interpretation of the treaty. SAM NUNN U.S. Senator (D-Ga.) Chairman, Committee on Armed Services Washington