Failures in complex technological systems could have multiple dire aftermaths, including many deaths and injuries. These events, such as nuclear accidents, pose serious threats and long-lasting health and environmental consequences to workers, the local public, and possibly the whole country and neighboring regions. Such failures,given interconnectivities and interdependencies, could also have spillover effects and threaten the integrity of other systems operating in the same area. There is an essential need for effective integration and interoperability among multiple emergency response agencies, possibly from different countries, in the case of an accident in a safetysensitive industry that causes the release of hazardous materials or contaminants. This article proposes a generic integrated system-oriented model to address this urgent need. It has been applied to the Persian Gulf area and its waters as a case study because of the existence of multiple co-located, safety-sensitive industries such as nuclear power generation, offshore oil and gas drilling, seawater desalination, and seafood harvesting. The Persian Gulf region and its ecosystems are highly vulnerable, and the countries around the Gulf are tightly interdependent, with an urgent need for cooperative emergency response planning. The Black Sea and other semiclosed, water-based ecosystems can also benefit from this model. Failures in complex technological systems could have multiple dire aftermaths, including many deaths and injuries. These events, such as nuclear accidents, pose serious threats and long-lasting health and environmental consequences to workers, the local public, and possibly the whole country and neighboring countries Such failures, given interconnectivities and interdependencies, could also have spillover effects and threaten the integrity of other systems operating in the same area. There is an essential need for effective integration and interoperability among multiple emergency response agencies, possibly from different countries, in the case of an accident in a safetysensitive industry that causes the release of hazardous materials or contaminants. This article proposes a generic integrated system-oriented model to address this urgent need. It has been applied to the Persian Gulf area and its waters as a case study because of the existence of multiple co-located, safety-sensitive ind ustries such as nuclear power generation, offshore oil and gas drilling, seawater desalination, and seafood harvesting. The Persian Gulf region and its ecosystems are highly vulnerable, and the countries around the Gulf are closely interdependent, with an urgent need for cooperative emergency response planning The Black Sea and other semiclosed, water-based ecosystems can also benefit from this model.