How can diplomacy be backed by economic sanctions or threats of force without becoming war?

Diplomacy can be backed by economic sanctions or threats of force to influence an adversary's behavior without escalating to full-scale war through strategies of coercion and economic statecraft.

Coercive Diplomacy and Signaling

Coercion aims to modify an opponent's behavior through bargaining and signaling, ideally using threats or limited, demonstrative force rather than brute force. This approach relies on convincing the adversary that the costs of non-compliance exceed the costs of changing their behavior.1

• Brinkmanship: This involves pushing an interaction to the threshold of confrontation to gain a negotiation advantage. While it carries high risks, the goal is to reach the "verge" of war to force a concession without actually triggering a conflict.2
• Gunboat Diplomacy: Historically, this involved the visible projection of naval power to intimidate states into negotiations or concessions. In the modern era, this has evolved into "signaling" through maritime patrols or freedom-of-navigation operations, which use a physical presence to assert legal or political stances without initiating hostilities.3

Economic Statecraft

Economic sanctions serve as a tool to pursue foreign policy goals, such as punishing human rights violations or preventing conflict, often as an alternative to military action. They function as "costly signals" that increase the credibility of a diplomatic stance. By imposing financial restrictions—such as asset freezes, trade embargoes, or travel bans—states can exert pressure while avoiding the high costs and destruction associated with war.45

However, these strategies carry risks: they can be counterproductive, invite retaliation, or cause unintended humanitarian harm. Success is often a matter of degree, and policymakers must weigh the relative utility of these coercive tools against the potential costs of military alternatives.154