“…Making this distinction not only is operationally important but also inherently recognizes that only some changes are of importance to the Coast Guard. For instance, a change in shipping densities and routes could be triggered by more than one driver, and a single driver can trigger changes in different domains (e.g., physical environment, 17 In other RAND work, permanent shifts in the security environment have been termed discontinuities and result from the response to a shock or set of shocks (see, for example, Hoehn et al, 2018). For example, the security sector's response to the terrorist attacks on September 11, 2001, resulted in a permanent shift in security posture, which has changed the demand for security-related operations and changed the regulatory environment.…”