What is "precommitment"

n. A prior commitment

Precommitment is a strategy in which a party to a conflict uses a commitment device to strengthen its position by cutting off some of its options to make its threats more credible. Any party employing a Strategy of Deterrence faces the problem that retaliating against an attack may ultimately result in significant damage to their own side. If this damage is significant enough, then the opponent may take the view that such retaliation would be irrational, and therefore, that the threat lacks credibility, and hence, it ceases to be an effective deterrent. Precommitment improves the credibility of a threat, either by imposing significant penalties on the threatening party for not following through, or, by making it impossible to not respond.

For instance, an army can burn a bridge behind it, making retreat evidently impossible. A famous example of this tactic is when Hernán Cortés had his men scuttle the ships in order to eliminate any means of desertion. Alternatively, in the context of the Cold War, fail-deadly retaliation systems such as the Soviet Dead Hand make a response to a sudden attack automatic, regardless of whether or not anyone is left alive to make decisions.

This strategy was discussed in detail by Thomas Schelling. It was important in 20th-century deterrence theory, as a threat must be credible to have deterrent power. Commitment devices used include tripwire forces waiting for a trigger event.