MY respect for Rabia Akhtar`s scholarship, `The correct narrative on Pressler` (May 29), is not diminished one iota by Senator Larry Pressler`s rebuttal (June 3). I af firm Rabia`s account: that the language of the amendment was purposely vague so as to allow for the waivers.

These waivers were anticipated because Pakistan needed help with Soviet troops next door. However, Capitol Hill was balking at providing aid to Pakistan because of its nuclear weapon-related programme. In this regard, Senator Pressler is entirely correct. Thus, continuing assistance to Pakistan required two artful compromises.

The first was between the Reagan administration and Zia. No one in the Reagan administration took Zia`s denials of a nuclear weapon programme seriously; there was compelling evidence to the contrary. Thus, promises were sought and given.

The most important aspect of Rabia`s research relates to uncovering the language of the State Department`s legal adviser, transmitted to the Congress in 1987. Here is what the legal advisor wrote: `Two considerations are key, recognizing that it is the President who must make any ultimate judgment. First, the statutory standard is whether Pakistan possesses a nuclear explosive device, not whether Pakistan is attempting to develop or has developed various relevant capacities. ... A distinction must therefore be drawn between the ability to achieve possession of a nuclear explosive device, and actual possession of such a device. Second, a state may possess a nuclear explosive device, and yet maintain it in an unassembled form for safety reasons or to maintain ef fective command and control over its use or for other purposes. The fact that a state does not have an assembled device would not, therefore, necessarily mean that it doesnotpossess a deviceunderthe statutory standard. A judgment concerning possession can only be made upon an evaluation of all relevant facts and circumstances of a particular case.

Now read between these lines: Pakistan possessed all but one of the key elements of a nuclear bomb at this time. The missing ingredient was highly enriched uranium.

For those of us who are not lawyers, everything about Pakistan`s nuclear programme at this time conveyed the clear impression of a country with both the ability and intent to make nuclear weapons.

But lawyers in service to power are sometimes obliged to split hairs and parse meaning. Thus, a second compromise was needed to continue supporting the ef fort to punish Soviet troops in Afghanistan while trying to look the other way about Pakistan`s nuclear activities. This is where the Pressler amendment and its tortured language came in: assistance to Pakistan couldnotbe providedifthe execudvebranch could not certif y that Pakistan was not in possession of a nuclear weapon.

As contortions of the English language go, it`s hard to beat the three negatives embodied in this key passage of the Pressler amendment. But these three negatives served the intended purpose of its draf ters.

(Rabia is correct that Senator Pressler was mostly an observer to this process, but he was willing to place his name on the final product.) And so, as long as Pakistan refrained from enriching uranium to weapons` grade, the State Department`s lawyers could advise the White House that Pakistan technically did not `possess` a nuclear weapon. The White House could waive sanctions. The Pressler amendment succeeded in its intended purpose.

Why did the Bush administration finally bring the hammer of the Pressler amendment down on Pakistan? Was this a betrayal of Pakistan by America? Most Pakistanis believe so.

Michael Krepon Washington DC