The logic of deterrence
An opponent may avoid attack when retaliation appears certain and costly. Military capability can therefore discourage opportunistic aggression.
Credibility requires preparation
A threat deters only if it appears believable. States therefore build weapons, train forces and plan for actions they claim they hope never to take.
Security dilemmas emerge
One country's defensive preparations may appear offensive to another. Each side then increases its forces in response to the other's fear.
Deterrence depends upon rational judgement
The theory assumes leaders understand signals, control their forces and avoid catastrophic miscalculation. History shows that mistakes and false alarms occur.
Nuclear deterrence raises extreme risks
Nuclear peace depends upon maintaining weapons capable of mass civilian destruction while ensuring they are never used accidentally or deliberately.
Alternatives can support security
Diplomacy, arms control, transparency, communication channels and conflict prevention can reduce dependence upon threats.
Evidence notes
Assessment should consider whether deterrence reduced attacks, intensified arms competition, increased accident risk, encouraged proxy warfare or prevented negotiated settlements.
Ethical questions
Can a threat to commit mass destruction be morally legitimate if it prevents war?
How much security can depend upon perfect judgement under pressure?
When does defensive preparation become provocative escalation?
Conclusion
Deterrence may prevent some wars, but it also institutionalises preparation for violence. Its moral and practical value depends upon whether risks are reduced overall, not merely whether weapons remain unused for a period of time.