Iron broke the Bronze Age empires because farmers could smelt it at home

Bronze is an alloy of copper and tin, and the tin in the weapons carried at Kadesh had to cross thousands of miles from mines that may have been in modern Afghanistan or Western Europe ^[4]. That distance from mine to forge is what the historical argument turns on. The difficulty of mining and transporting tin is one reason bronze weaponry stayed concentrated in military and elite institutions, while the average citizen worked copper, stone, bone and wood ^[5]. Iron removed the journey. Because iron could be produced locally, the essay argues, imperial centers no longer held such a strong advantage over their subject peoples, and the political equilibrium changed for good ^[7].

Bronze weapons start appearing in the archaeological record around 3000 BC ^[11]. Count forward to the catastrophes of around 1200 BC ^[8] and that is roughly eighteen hundred years in which those armies depended on an imported metal ^[16]. The Copper Age before it ran about two thousand years ^[17].

Copper's own history points the other way. Groups holding copper weapons pushed into surrounding communities that used stone tools, beginning a round of prehistoric political consolidation, and the period leaves behind more fortified settlements, more unequal grave goods, and smelting sites as far as sixty miles from where the copper was mined ^[13]. Bronze later displaced it because bronze is harder and stiffer and holds a sword's edge longer ^[14].

The essay says access to the tools of violence has been exceptionally concentrated in our era, allowing superpowers far larger than those of the late Bronze Age to reign largely unchallenged, and that as military technology evolves "another age of upheaval may be approaching" ^[15]. Its opening line asks, "Could technologies like drones do the same today?" ^[1]. No cost or production figures accompany either passage ^[18].

The essay's answer to the standard account is that catastrophes of that kind often create political upheaval without permanently ending civilizations, so the thing needing explanation is the centuries in which nothing comparable returned ^[9]. That interval is measured in centuries. An argument pitched on that scale tells a company or a ministry little about where it will stand in three years. It does carry one test that can be applied now: for any weapon getting cheaper, ask where it can be made and by whom ^[5][7].