This chapter uses Mass Observation (MO) survey material to assess initial responses to the outbreak of war in the summer of 1950. It first explores the utility of MO surveys and diaries to the social history of the war, before analysing responses in detail, alongside early television and newspaper reports. It concludes that the first few months of the Korean War were a worrying time for many Britons, as anxieties gathered around several areas: aerial attack, nuclear warfare and the mobilisation of male citizens.