MISLEADING

The claim correctly describes nuclear fusion but incorrectly identifies it as the standard third and final stage of a thermonuclear weapon. Most modern warheads use the two-stage Teller-Ulam configuration, consisting of a fission primary and a fusion secondary; in this standard design, there is no third stage (Center for Arms Control and Non-Proliferation, 2022). High-yield weapons are often described by a fission-fusion-fission cycle, where the third and final step is actually the fast fission of a uranium-238 tamper by high-energy neutrons, which can account for more than half of the total explosive yield (Marsh, 1949; Morland, 1979). While a few true three-stage weapons like the Soviet Tsar Bomba or the American B41 were built with a tertiary fusion stage, these are historical exceptions rather than the rule for thermonuclear weaponry (Wikipedia, 2024; Atomic Heritage Foundation, 2023).