Abstract This chapter examines how a change in the expectation of complete victory moderates the effect of popular nationalism through the Falkland/Malvinas Islands dispute between Argentina and Great Britain. Specifically, it investigates the impact of popular nationalism on Argentina’s choice between war and the status quo. This chapter shows that a country can quickly slide into war when leaders’ belief in their chance of complete victory shifts amid strong popular nationalism. Despite the public’s intense nationalistic sentiments, Argentinean leaders did not consider using force in the early phase of the territorial dispute and instead opted for the status quo. Only after the Argentinian junta was convinced of its chance of complete victory did popular nationalism have a conflict-inducing effect, sparking the Falklands War in 1982.