Igor Diakonoff and Sergei Starostin have suggested that Nakh is distantly related to Hurro-Urartian, which they included as a branch of the Northeastern Caucasian language family (which were dubbed Alarodian languages by Diakonoff). Several studies argue that the connection is probable. Other scholars, however, doubt that the language families are related, or believe that, while a connection is possible, the evidence is far from conclusive. Various interpretations of the Nakh-Urartian relationship exist: another, held by Kassian (2011), is that Urartian and Nakh's common vocabulary instead reflects a history of intense borrowing from Urartian into Nakh.