This chapter adopts a working definition of linguicide as “the deliberate act of killing a language,” and then argues that such a policy is synonymous with ethnocide – “the deliberate and systematic destruction of the culture of an ethnic group1”. Linguicide and ethnocide are then presented as something that can and should be regarded as a form of genocide, as defined by the 1948 International Convention on the Prevention and Punishment of the Crime of Genocide. Following this, the chapter provides a broad, general overview of twentieth and early twenty-first-century policies of the Iraqi, Turkish, Iranian, and Syrian states towards their Kurdish populations and the Kurdish language in particular. We find that while Iraqi state policy could at no time be classified as linguicidal, Turkish and Syrian state policies did fit the criteria for linguicide. Iranian state policy after the first Pahlavi monarchy (which did try to engage in linguicide) presents a more complex picture, with evidence for an intentional, deliberate policy to destroy the Kurdish language being harder to establish conclusively. The analysis here encourages readers to distinguish between attempts to Arabize, Turkify, or Persianize a population and linguicide. While the former can and do include significant levels of coercion and ethnic chauvinism, they do not necessarily constitute linguicide. Linguicide involves more than trying to establish a single nationwide language and culture. Linguicidal states view other languages and cultures within the country as threats and hence attempt to destroy them.