Questions: Second-Strike Capability and Nuclear Stability

Question 1

State A develops a comprehensive missile defense system capable of intercepting most of State B's nuclear warheads. According to strategic stability theory, this development is most likely to:

• A. Increase stability, because State A can now defend its population against retaliation and has less reason to strike first
• B. Decrease stability, because State A might now consider launching a first strike, calculating it could absorb the weakened retaliation
• C. Leave stability unchanged, because missile defense does not affect the number of offensive warheads either side possesses
• D. Increase stability, because mutual defensive capability reduces incentives for offensive nuclear buildup

Answer: (B)

This is the central paradox of MAD stability: defenses undermine it. If State A believes its missile defenses can intercept most of State B's retaliatory strike after a first strike, State A might calculate that a disarming first strike is survivable — destroying most of State B's weapons, then absorbing the weakened remainder with its defenses. State B, knowing this, faces use-it-or-lose-it pressure to strike before State A can strike first. The 1972 ABM Treaty deliberately limited missile defenses for exactly this reason: mutual vulnerability, not mutual defense, was understood to be the foundation of stable deterrence.

Question 2

Country A possesses 2,000 land-based nuclear missiles in known fixed silos. Country B possesses 200 submarine-launched ballistic missiles on patrol. Which country has more secure second-strike capability?

• A. Country A, because 2,000 warheads provides more retaliation options than 200
• B. They are equivalent, because total warhead count is what determines deterrence credibility
• C. Country B, because submarines are survivable against a first strike while fixed silos are targetable and can be destroyed preemptively
• D. Country A, because an attacker cannot realistically destroy all 2,000 missiles simultaneously

Answer: (C)

Second-strike capability is about survivability, not quantity. Fixed silos in known locations can be targeted in a coordinated first strike — a country with 2,000 land-based missiles might end up with very few after a well-executed preemptive strike. Submarines on patrol are essentially unfindable, so all 200 of Country B's warheads survive a first strike and remain available for retaliation. The practical implication is that a small survivable force can provide more credible deterrence than a large but vulnerable one. Quantity matters only insofar as it survives to be delivered.

Question 3

Mutual Assured Destruction is most stable when one side achieves clear nuclear superiority, because the dominant power has a first-strike advantage that makes war irrational for the weaker side.

• T. True
• F. False

Answer: False

MAD stability requires mutual vulnerability, not one-sided superiority. If one side achieves genuine first-strike capability — the ability to destroy the other's retaliatory forces in a preemptive strike — the weaker side faces use-it-or-lose-it pressure and the stronger side faces temptation to exploit its advantage. Superiority produces instability, not stability. Stability in the MAD framework depends on both sides being unable to prevent devastating retaliation — a condition of mutual vulnerability that makes first strikes irrational for both parties simultaneously.

Question 4

The 1972 Anti-Ballistic Missile Treaty deliberately limited missile defense systems because mutual population vulnerability was understood to be the foundation of stable nuclear deterrence.

• T. True
• F. False

Answer: True

The ABM Treaty is the clearest historical example of states institutionalizing the paradox of MAD: that security comes from vulnerability, not defense. Both the US and USSR agreed to cap their missile defenses precisely because extensive defenses would undermine MAD stability by potentially allowing a first strike followed by absorption of the weakened retaliation. The treaty acknowledged that allowing the enemy to destroy your cities in retaliation is the price of a stable nuclear peace — and that building defenses to escape this threat would make war more, not less, likely.

Question 5

Why is a small, survivable nuclear force potentially more stabilizing than a larger but vulnerable one?

Model answer: Nuclear stability depends on the credibility of retaliation, which requires that retaliatory forces survive a first strike — not that there are many of them. A large force in fixed, targetable locations may be largely destroyed in a disarming first strike, leaving few weapons available for retaliation and undermining deterrence credibility. A small force on submarines or otherwise concealed cannot be preemptively destroyed, guaranteeing that retaliation will occur regardless of what the adversary does. This guarantee is what makes the deterrent credible and the first strike irrational. Survivability, not quantity, is the operative variable.

The implication is that arms races focused on numbers can be destabilizing if they produce forces that are large but targetable. The strategic logic of MAD rewards survivability over size — which is why submarine forces became the foundation of secure deterrence for every major nuclear power, and why the vulnerability of land-based forces in fixed silos creates the crisis-stability problems described in the Explainer.