Biological Weapons Convention Enters into Force

Context

The 1925 Geneva Protocol had prohibited the use of biological and chemical weapons in war, yet it left open the possibility of development, production, and stockpiling. Several major states maintained offensive biological weapons programs in the decades that followed, viewing them as potential deterrents or battlefield options despite the protocol's restrictions. Reservations attached by many signatories further limited the agreement to a no-first-use pledge in practice.

By the late 1960s, growing international concern over weapons of mass destruction, combined with progress on nuclear nonproliferation, shifted attention in United Nations disarmament forums toward biological weapons specifically. A British proposal in 1968 suggested negotiating a ban on biological weapons separately from chemical ones to break a longstanding deadlock. Momentum increased when the United States announced in 1969 that it would unilaterally end its offensive biological weapons program and redirect efforts solely to defensive research.

What Happened

Negotiations proceeded in the Conference of the Committee on Disarmament in Geneva from 1969 onward. The Soviet Union and its allies, which had previously opposed separating biological from chemical weapons talks, reversed course in March 1971 and submitted their own draft convention. On August 5, 1971, the United States and the Soviet Union each tabled identical draft texts, clearing the way for broader agreement. The United Nations General Assembly endorsed the final text in December 1971.

The Convention on the Prohibition of the Development, Production and Stockpiling of Bacteriological (Biological) and Toxin Weapons and on Their Destruction was opened for signature on April 10, 1972, with simultaneous ceremonies in London, Moscow, and Washington, D.C. The three depositary governments—the United States, the United Kingdom, and the Soviet Union—along with other states began the ratification process. The treaty required ratification by 22 states, including the three depositaries, to enter into force.

That threshold was reached in early 1975. On March 26, 1975, the Biological Weapons Convention officially entered into force, binding its initial parties to forgo development, production, stockpiling, acquisition, or retention of biological agents and toxins for hostile purposes, as well as related weapons and delivery systems.

Aftermath

The 22 ratifying states, including the major powers, became the first parties to a comprehensive ban on an entire class of weapons of mass destruction. Existing stockpiles in states that had maintained offensive programs were slated for destruction or conversion to peaceful uses under the treaty's provisions. The entry into force established immediate legal obligations for national implementation measures and consultation among parties on compliance issues.

Legacy

With 189 states parties as of 2025, the convention has created a near-universal norm against biological weapons that remains in force without time limit. It complemented later agreements on chemical and nuclear weapons while underscoring persistent difficulties in verification and enforcement, as evidenced by subsequent revelations of violations by the Soviet Union and Iraq. Periodic review conferences have addressed advances in biotechnology, yet the absence of a formal verification protocol continues to shape debates on strengthening the regime against misuse of life sciences.