The concept of "resilience" originated in both ecology and psychology, and refers to the propensity of a system or entity to "bounce back" from a disturbance. Recently, the concept has found increasing application within linguistics, particularly the study of endangered languages. In this context, resilience is used to describe one aspect of long-term, cyclical changes in language vitality. Proponents of "resilience linguistics" argue that understanding long-term patterns of language vitality can be of use in fostering resilience in, and therefore maintenance of, endangered languages. This article takes a critical look at these proposals, based on the examination of long-term trends in the Monguor and Saami languages.