The Soviet Union increased its biological weapons research in 1949.

Evidence

But the Russians were frightened, actually; they subsequently vastly ramped up their own biological-weapons research program. — Nicholson Baker, Baseless- My Search for Secrets in the…, 914

Categorization

• corroborated: 3 independent passages support this claim — Nicholson Baker, Baseless- My Search for Secrets in the…, 914