Both threats and assurances can be useful in international negotiations. Threats help convince the adversary that a state will fight if challenged, and assurances can convince the adversary that a state will not attack if not challenged. We develop a model that analyzes when threats and assurances are used. Threats are widely useful because there is typically a range of outcomes that are preferable to war for each side, and threats can secure a better deal within that range by strengthening a state's bottom line. In contrast, assurances are only necessary when war would result without them because of insufficiently valued intermediate outcomes or shifting power. We discuss insights from the model, including the role of false assurances, in the context of both the Sudetenland Crisis and Cold War Europe.
2We will never be an aggressor. We want adequate security. We want no more than adequacy. But we will accept nothing less. President Eisenhower, November 13, 1957. President Eisenhower's statement during a speech about the Soviet Union combined a threat and an assurance. By saying that the U.S. would accept nothing less than security, he issued a threat that any infringement on U.S. security would be met with force. By combining it with an assurance that the U.S. wanted nothing more than security, he disavowed any interest in changing the status quo by force. Threats and assurances are often thought to be complementary. Threats bolster a state's resolve, reducing the adversary's incentive to attack out of greed, while assurances lessen the adversary's security concerns, reducing its incentive to attack out of fear.This logic suggests that threats and assurances should be used together, since they maximize the likelihood that the adversary complies with a state's demand. However, the picture is more complicated. Previous scholarship indicates that both threats and assurances may involve tradeoffs. Threats strengthen one's bottom line in bargaining, but can make war more likely. Meanwhile, assurances make peace more likely, but may weaken one's bargaining position. Therefore, leaders may not always prefer to make both types of statements.The potential tradeoffs associated with threats and assurances suggest that the theoretical rationales for both types of statements need to be examined more closely to see when each is needed. Analyzing when threats and assurances are necessary will not only enrich our understanding of the bargaining model of war, but also has the potential to provide practical insights for policymakers who are seeking to peacefully compel or deter an adversary.We introduce a formal model of threats and assurances in the context of an international crisis. Threats to fight if the other side goes too far generate an audience cost that is paid if a state fails to fight. Assurances not to attack if the other side does not go too far generate an audience cost that is paid if a state engages in unprovoked aggression. We find that threats strengthen a state's bottom line and hence are generally useful in b...