Legal Definitions - casus foederis

Casus foederis refers to an event or situation that triggers a specific obligation or right under a formal agreement, such as a treaty between nations or a commercial contract. It signifies that the conditions agreed upon by the parties for a particular action or response have been met.

• International Alliance Example: Imagine two countries, Alpha and Beta, have a mutual defense treaty. This treaty states that if either country is subjected to an unprovoked military invasion, the other country is obligated to provide military assistance. If Country Alpha is suddenly invaded by Country Gamma without provocation, this invasion becomes the casus foederis. It is the specific event that triggers Country Beta's obligation to deploy its forces and defend Country Alpha, as stipulated in their alliance.

• Commercial Contract Example: Consider a contract between a software company and a client for a custom application. The contract specifies that the software company will provide emergency technical support within two hours if a critical system bug prevents the client's core business operations. If such a bug occurs, causing a complete shutdown of the client's operations, this system failure is the casus foederis. It is the precise event that activates the software company's contractual duty to respond promptly and begin troubleshooting.

• Insurance Policy Example: A homeowner purchases an insurance policy that covers damage to their property specifically from named perils like fire, theft, or severe storms. If a lightning strike causes a fire that damages the roof of their house, this fire is the casus foederis. It is the event that falls directly within the terms of the insurance policy, thereby triggering the insurance company's obligation to cover the repair costs according to the policy's provisions.