Throughout the COVID-19 pandemic, militaries around the world mobilized at an unprecedented scale to support domestic response efforts. This was consistent with the growing trend of asset mobilization for military operations other than war during public health emergencies. However, the global scale and vast breadth of civil-military cooperation during the pandemic invites new considerations regarding the authority and scope of domestic operations of militaries during public health emergencies. We have systematically analyzed domestic military deployment policies in each UN member state, focusing on the authority, execution and scope of military involvement pertaining to domestic public health emergencies.  We analyzed legally enforceable policies, including Constitutions, defense ministry authorizations, and legal frameworks. We categorized how each country codified the deployment of military assets, who holds authority for deployment and the procedural mechanisms for deployments. Our findings revealed that of countries with active military forces, nearly all (170/171) have codified rules on domestic military deployment and  90.59% (154/170) allow military mobilization through executive orders. Furthermore, 58.48% (100/171) of countries with an active military have codified separation of powers to ensure that civilian decision makers are exclusively empowered to mobilize military forces. Finally, we found that 74.85% (128/171) of countries included language that authorized military involvement in domestic military operations other than war.    Our findings provide critical data for analyzing the relationship between military operations and public health outcomes, including how specific domestic military deployment policies impact the speed and effectiveness of military involvement in public health emergencies.

The authors have declared no competing interest.

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