Page 20 - 《国际安全研究》2021年第5期

超越“确保摧毁”：核武器数量、承诺可信度与核威慑原理

期成本远低于直接实施核报复的预期成本，因此更加可信。 以这种方式实现威慑
①
的关键是，威慑方必须设法将事态推向失控的边缘，使冲突的进程和前景在一定程
度上超出冲突双方的主观可控范围。
②
这种威慑方式生效的过程类似下面这种情境：两个人被绳子绑在一起站在悬崖边，
显然，其中任何一人对另一人说“你如果攻击我，我就把你推下悬崖”，后者都不会相
信。但前者可以故意把两人尽量拖向悬崖边缘，甚至一只脚悬空，从而造成一种随时

可能失控的不稳定状态。此时，两人的任何肢体碰撞，或者脚下石子滑落，甚至一阵
风，抑或前者恐高引起的眩晕，都有可能使两人跌下悬崖，此时停止攻击、主动后退
③
就会成为后者的理性选择。 这种威慑方式也因此被称为“边缘策略”（brinkmanship）。
另一个类似的情境是两个不会游泳的人在一条独木舟上，其中一人为慑止另一人的攻

击，显然不能以将舟弄翻相威胁，但前者可以将舟左右摇晃。舟摇晃的幅度越大，两
人淹死的风险就越大，但同时，后者为规避这一风险而停止攻击的概率也越大。
④
从上述情境所展示的威慑生效原理可以看出，在冲突失控将给双方都造成不可

承受的损失的情况下，博弈双方谁愿意承担更大的失控风险，谁就能够迫使另一方
⑤
让步。 愿意承担的失控风险大小反映的是在冲突中坚持下去的决心（resolve），

① Robert Powell, “Crisis Bargaining, Escalation, and MAD,” The American Political Science
Review, Vol. 81, No. 3, 1987, p. 719.
② Thomas C. Schelling, The Strategy of Conflict, Cambridge, MA: Harvard University Press,
1960, p. 188.
③ 参见 Thomas C. Schelling, Arms and Influence, New Haven: Yale University Press, 1966, p. 99。
④ 参见 Thomas C. Schelling, The Strategy of Conflict, Cambridge, MA: Harvard University
Press, 1960, p. 196; Thomas C. Schelling, Arms and Influence, New Haven: Yale University Press,
1966, p. 91。
⑤ Thomas C. Schelling, Arms and Influence, New Haven: Yale University Press, 1966, pp.
92-125; Glenn H. Snyder and Paul Diesing, Conflict among Nations: Bargaining, Decision Making,
and System Structure in International Crises, Princeton: Princeton University Press, 1977, pp. 456-458;
Robert Jervis, “Deterrence Theory Revisited,” World Politics, Vol. 31, No. 2, 1979, pp. 291-292;
Robert Jervis, “Why Nuclear Superiority Doesn’t Matter,” Political Science Quarterly, Vol. 94, No. 4,
1979/1980, p. 631; Kenneth N. Waltz, “Toward Nuclear Peace,” in Robert J. Art and Kenneth N. Waltz,
eds., The Use of Force (Second Edtion), Lanham: University Press of America, 1983, pp. 589-590;
Robert Jervis, The Illogic of American Nuclear Strategy, Ithaca: Cornell University Press, 1984, pp.
126-46; Robert Powell, “The Theoretical Foundations of Strategic Nuclear Deterrence,” Political
Science Quarterly, Vol. 100, No. 1, 1985, p. 78; Richard K. Betts, Nuclear Blackmail and Nuclear
Balance, Washington D.C.: The Brookings Institution, 1987, pp. 11-12; Robert Jervis, The Meaning of
the Nuclear Revolution, Ithaca, NY: Cornell University Press, 1989, pp. 38-41, 105; Robert Powell,
Nuclear Deterrence Theory: The Search for Credibility, Cambridge: Cambridge University Press, 1990,
pp. 33-45; Robert Powell, “Nuclear Deterrence Theory, Nuclear Proliferation, and National Missile
Defense,” International Security, Vol. 27, No. 4, 2003, pp. 89-97.

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