Warfare didn't exist in that form; it was too early for his military model. Agricultural spread (7000 BC)
Drews contends that the "Indo-Europeanizing" of Europe began around . He identifies military conquest, rather than agricultural diffusion or simple migration, as the primary catalyst for the spread of Greek, Keltic, Germanic, and Italic languages. Militarism and the Indo-Europeanizing of Europe
Critics argue that evidence of pre-1600 BC mass combat (such as the Tollense River massacre site ) contradicts his late timeline. Warfare didn't exist in that form; it was
Language didn't move with seeds; it moved with weapons and specialized warriors. Warfare didn't exist in that form
The introduction of chariot warfare and large-scale "battlefield warfare".