A recent class of public health initiatives has the morally questionable consequence of crossing borders; more specifically, they are initiated by one state but have significant resultant impacts on neighboring states. One clear case of this is genetically modified mosquitoes: mosquitoes are difficult to contain within state boundaries and often crossover whereby associated risks are thrust upon neighboring states. While nuances of laws and international policies are crucial considerations, this paper explores the underlying ethical considerations relevant to such classes of border-crossing public health initiatives. I begin with an explication of what makes these initiatives intuitively wrong at the individual level, and I identify three key moral violations: violations of property rights, exposure to harm, and lack of consent. I then capture these issues under the general umbrella of justifying paternalistic actions and take states as moral agents responsible for complying with certain moral obligations. The following question arises: if neighboring states do not agree to the initiatives, are there good reasons of proceed regardless? I appeal to existing analogues in public health as the standard for moral legitimacy and distill their structure of justification. First, there is a structurally “cosmopolitan” justification which appeals to the positive consequence for the global community. Second, there is a “perfectionist” justification which appeals to the goods bestowed upon the dissenting state. Third, there is a “free-rider” type of justification which frames dissent as morally wrong. I argue that border-crossing initiatives are at least consistent with the moral justification of recent public health initiatives insofar permitting certain sorts of paternalistic actions. I then suggest a defensible fourth way of justifying such initiatives by making appeal to a state’s obligations to its own citizens.