This study looks at the roles that WhatsApp, the popular smartphone application, played in the lives of Israeli citizens, who were exposed to war menaces during July 2014. During the war, WhatsApp became the subject of public, media, and political discourse, especially within the context of disseminating information related to combat – ‘authentic’ news items (before they were published in the media) alongside rumors that were devoid of factual basis. Research questions focused on the ways in which citizens used the application, the attributed effects of that usage on their lives, and the possible connections between proximity of residence to combat areas, patterns of usage, and perceived implications. Data are based on a representative survey of 500 Israeli citizens aged 16–75, all of whom are smartphone users (maximum sample error 4.5%). The survey was conducted during the third week of the military operation ‘Protective Edge’, which took place between Israel and Hamas in the summer of 2014. The authors’ findings suggest that WhatsApp played a central multi-functional role in the lives of its users during the wartime, functioning as a mass as well as interpersonal communication channel. Participants used the application on a daily basis for various purposes: getting news and updates regarding the war; checking on their loved ones; delivering humorous satirical messages; spreading war-related rumors; and helping to promote voluntary aid initiations. Users expressed their beliefs that the application enabled them to stay updated and ‘in the know’, helped them calm down, and deepened their communal and national sentiments. While findings regarding WhatsApp and similar applications usages have been collected for the last few years, this research exposes its centrality under extreme circumstances. Further on, this work suggests that WhatsApp may be thought of as a unique combination of mass and interpersonal communication channels.