Provided are a computer program product, system, and method for using a declaration of security requirements to determine whether to permit application operations. A declaration of security requirements indicates actions the application designates to perform with respect to resources in a computer system, wherein a plurality of the indicated actions are indicated for at least two operation modes of the application. A detection is made of whether the application is requesting to perform a requested action with respect to a requested resource in the computer system. A determination is made of a current operation mode of the application comprising one of the at least two operation modes in response to detecting that the application is requesting the requested action. A determination is made as to whether the declaration of security requirements indicates the requested action with the current operation mode. The requested action with respect to the requested resource is allowed to proceed in response to determining that the declaration of security requirements indicates the requested action with respect to the requested resource as indicated with the current operation mode.