Persistent and increasingly detailed accounts of Soviet chemical warfare in Afghanistan and elsewhere are strenghtening arguments that the United States should develop its own neglected chemical warfare capability as a deterrent.
Experts of the Departments of State and Defense, and a Harvard University scientist, told a congressional hearing April 24 of growing evidence that the Soviets have used incapacitating gas against Muslim rebels in Afghanistan. But, they said, proof is lacking to substantiate reports of lethal nerve gas attacks by the Soviets.
State Department counselor Matthew Nimitz said the evidence was still about " 50- 50" that fatal casualties occurred from use of gas in Afghanistan. Accounts of refugees and others were conflicting in some cases and "inconsistent" in others, he explained.
Dr. Matthew Messelson of Harvard University, a chemical warfare expert who has investigated past alleged use of gas in Vietnam and Laos, as well as the Afghan reports, said: "There are many questions to be answered, and we must continue our investigations."
In responding to questions by chairmen Clement J. Zablocki (D) of Wisconsin and Lester L. Wolff (D) of New York of the House subcommittees on Asia and international affairs, Mr. Nimitz said the government felt the burden of proof should not be on the US, but that other governments and world humanitarian bodies should more actively seek to establish the truth. Violation of the 1925 International Conventions against the use of chemical and biological warefare (CBW) which the Soviet Union as well as the US and all other major governments signed, was a matter for the world community as a whole to investigate.
Several congressmen questioned witnesses about a recent letter to Congress from Defence Secretary Harold Brown arguing that the US should develop its own chemical weapons as a deterrent to the superior and growing chemical-weapons capacity of the Soviet Union and Warsaw Pact countries.
The US Army, like Mr. Brown in his letter, argues that the Army should be given authority and funding to manufacture a new type of chemical munition. So far such authorization has been blocked by some congressmen and some members of the White House staff.
These "binary" weapons are shells and bombs containing nontoxic chemicals which are combined into toxic form just before the shell or bomb explodes on its target.
The Army wishes to replace its current stock of gas weapons, especially those using a nerve gas called Sarin, which are aging and in some cases leaking, with binary devices better suited to retaliation against any Soviet first use of chemical warfare.
A stockpile of so-called "weteye" chemical nerve agent bombs was to have been moved from its storage place at Rocky Mountain Arsenal in Denver to a safer Army depot in Utah. But on Feb. 26 the Defense Department announced it would keep the weteye bombs where they are to preclude "even the minimal risks" involved in moving them.
On April 24 the Stockholm International Peach Research Institute (CIPRI) released a book-length report called "Chemical Weapons: Destruction and Conversion," with detailed accounts of chemical disarmament progress.
"Development of chemical warfare devices has continued without interruption, particularly in the arsenals of the. . . US and USSR," the CIPRI report asserts. Though the 1925 Geneva Protocol forbids first use of chemical weapons in war, it does not ban their manufacture. US and Soviet negotiators have been discussing renunciation of first use in the Committee on Disarmament and previous bodies since 1977 without significant progress.
Witnesses at the April 24 committee hearings here emphasized that in signing the 1925 agreement the Soviets had made a reservation concerning use of chemical warfare involving countries not signing the protocol. One of these nonsigners was Afghanistan.