Science Quote by Joseph Rotblat

Rotblat’s sentence has the clipped precision of a scientist trying to remove every comforting loophole. By calling deterrence the "only function" of nuclear weapons, he shrinks the entire strategic mythology - prestige, leverage, warfighting doctrines, "limited" nuclear options - down to a single grim purpose: preventing the thing they are built to do. It’s an argument that works by refusing the usual euphemisms. No talk of "stability" or "balance". Just a stark claim about function, like an engineering spec for a device that must never be switched on.

The intent is moral and technical at once. Rotblat isn’t asking whether nuclear weapons can win wars; he’s implying that any attempt to give them additional roles is a category error that turns deterrence into a pretext. Once nukes are treated as usable tools - for coercion, escalation management, or "signaling" - the premise of deterrence starts to rot from within. Deterrence depends on the credibility of retaliation, but safety depends on the unthinkability of use. That contradiction is the subtext: the system asks leaders to be simultaneously rational enough to avoid catastrophe and irrational enough to threaten it.

Context sharpens the edge. Rotblat left the Manhattan Project when Germany was no longer a nuclear threat, then spent decades as a dissident insider, a physicist insisting that technical capability doesn’t confer ethical permission. In the Cold War, his line reads like a warning against normalizing the bomb: if its only legitimate role is to prevent itself, then the "while they exist" clause becomes the real indictment. Deterrence is not a job description; it’s a holding pattern.