1. QR 38 Cuban Missile Crisis, 4/26/07 I. Background II. Uncertainty about Soviet type III. Brinksmanship

2. I. Historical background to crisis October 1962: US discovered that Soviet Union was installing nuclear missiles (MRBMs) in Cuba This represented a significant increase in the risk to the US, because these weapons could reach US soil much faster than ICBMs; and the Soviets only had a couple of ICBMs. Missiles were probably there to deter US invasion of Cuba

3. Response of Kennedy administration JFK did not immediately share the fact that the US had discovered the missiles with the Soviet Union, or make any public announcements Instead, convened ExComm ExComm met in secret over about a week to work out appropriate response; know a lot about their deliberations now

4. Initial Reactions Initially, understood the choice to be between military action (supported by JCS) and focusing on a purely diplomatic solution (Stevenson) The immediate risk of doing nothing acceptable, but Kennedy aware that the missile installations could continue and worried about US loss of face in larger Cold War picture

5. Blockade option Robert McNamara, Secretary of Defense, came up with the idea of a blockade or “naval quarantine” This was attractive because it greatly reduced the risk of nuclear war; but JCS continued to resist Eventually consensus formed around use of blockade

6. Blockade Imposed Kennedy announced discovery of missiles and imposition of blockade on October 22, one week after missiles first discovered. Navy directed to set up blockade closer to Cuba than its usual procedures specified, and to be lenient about letting civilian boats through In practice, Navy mostly followed SOPs.

7. Negotiations Soviets responded to Kennedy’s announcement by looking for ways to end crisis, while publicly hanging tough Soviet Presidium made early decision not to let crisis escalate to war, but didn’t make this public Began quietly exploring deal that would get missiles out of Cuba in exchange for US commitment not to invade Cuba, and US Jupiter missiles out of Turkey

8. Crisis resolution Soviets ordered ships with military cargo to turn back Khrushchev sent Kennedy private, conciliatory letter on Oct. 26, am Later that day publicly sent a tougher letter, adding missile swap to conditions US agreed but insisted that missile swap be kept secret

9. II. Uncertainty about Soviet type This is a game of compellance: The US attempting to compel the Soviets to withdraw Using threats to accomplish this; but imposing the threat would be costly for both sides. US uncertain about how hard-line Soviets were; i.e., whether they preferred withdrawal or defiance in face of US threat

10. Game with uncertainty Nature Soviets hard-line (p) Soviets soft (1-p) US Threat No Threat No -2, 2 Withdraw Defy Withdraw Defy 1, -8 -10, -4 1, -4 -10, -8 SU

11. Equilibrium If the Soviets are hard-line, they get a payoff of -8 from withdraw and -4 from defy, so they with defy So if the US know the Soviets were hard- line, shouldn’t make the threat If the Soviets are soft, they will withdraw So if the US knew the Soviets were soft, US should make the threat

12. Critical value of p The US expected payoff from threat is p(-10) + (1-p)(1) = 1-11p US payoff from no threat is -2 So US should threaten if 1-11p>-2 11p<3 p<3/11 (.27)

13. US strategy Can think of.27 as the upper limit of US tolerance for risk Kennedy’s statements suggest that he thought the probability that the Soviets were hard-line was between.33 and.5 So too risky for US to use threat of war The threat is “too big” to be credible

14. III. Brinksmanship So, Kennedy turned to alternative strategy, brinksmanship Brinksmanship is the use of a threat that leaves something to chance; a probabilistic threat Using brinksmanship involves giving up some freedom of action, i.e. of reducing risk

15. Modeling brinksmanship Brinksmanship is the creation and control of risk US had to create some risk of war; but not too high, or wouldn’t be credible Model this by introducing a probability, q, with which war will occur if Soviets defy

16. Payoff with risky threat US payoff at defy outcome is now -10 (war) with probability q and -2 (same as doing nothing) with probability 1-q So expected US payoff is -10q+(1-q)(-2) = -2-8q Soviet hard-line payoff is -4(q)+2(1-q) = 2-6q Soviet soft payoff is -8(q)+2(1-q)=2-10q

17. Brinksmanship game Nature Soviets hard-line (p) Soviets soft (1-p) US Brink No Brink No -2, 2 Withdraw Defy Withdraw Defy 1, -8 -2-8q, 2-6q 1, -4 -2-8q, 2-10q SU

18. Soviet strategy What value of q will compel the Soviets to withdraw? If hard-line, need -8>2-6q 6q>10, q>1; can’t satisfy So US can’t compel hard-line to withdraw by using brinksmanship

19. Soviet strategy If Soviets are soft, will withdraw if -4>2-10q 10q>6 q>.6 So US could induce soft Soviets to withdraw by setting q above.6 This is the effectiveness condition

20. US strategy What is the critical value of q that will lead the US to use brinksmanship? That will depend on p Expected value of making the threat is p(-2-8q)+(1-p)(1) = -8pq-3p+1 So should make the threat if -8pq-3p+1>-2 q<3/8((1-p)/p) This is the acceptability condition

21. Results When p<.27, q=1 is in the acceptability zone, so a full threat can work. When.27<p<.38, full threat not acceptable (need q<1), but there is a range between.6<q<1 that can work So some scope for brinksmanship

22. Brinksmanship in practice In the crisis, the US blockade created the risk of war and so worked as a brinksmanship strategy Because Kennedy didn’t know the precise values of p and q, began with small threats (very low value of q) and gradually increased until the Soviets backed down This did, though, run some risk of nuclear war

23. When can brinksmanship work For brinksmanship to work, need to be able to satisfy both the effectiveness and acceptability conditions If q too low, won’t be effective If q too high, US won’t be willing to bear the risk Capture these considerations in a graph