Book excerpt: The 2016 US election highlighted the potential for foreign governments to employ social media for strategic advantages, but the particular mechanisms through which social media affect international politics are underdeveloped. This Element shows that the populace often seeks to navigate complex issues of foreign policy through social media, which can amplify information and tilt the balance of support on these issues. In this context, the open media environment of a democracy is particularly susceptible to foreign influence whereas the comparatively closed media environment of a non-democracy provides efficient ways for these governments to promote regime survival.