Bret Devereaux

There's truth to that characterization, which I think is illustrative here: Rome's allies, in many cases, stayed allies (while they did) because it was in their interest. The Italian allies of Rome (the socii) got their share of the loot, got to march in the victory parade...2/

...and even seem to have had access to settlement in colonies founded on seized land. Obviously, the USA is not going to pillage non-NATO countries to provide goodies to handout to wavering NATO members, that's not what I'm suggesting 3/

And I'm also not saying Rome wasn't willing, at points, to be staggeringly brutal in keeping its allies in line. But that brutality had limits - Rome couldn't hold Italy by pure force of arms alone, and they knew it, and they didn't try. 4/

The limits to coercion appear quite clearly in both 209 and 90. In 209, with Hannibal in Italy, 12 allied communities in Italy essentially refuse to send anymore soldiers (claiming they have none). The senate wags its finger, but does nothing (Liv. 27.10.10) 5/

(I promise this will come to a point relevant to the modern world soonish). In 90, faced with widespread revolt among the allies, the Romans are forced to rely on carrot, rather than stick and offer Roman citizenship, with its attendant privileges, to any who laid down arms. 6/

My point being that the system here is both carrot-and-stick, and the Romans often got more mileage out of the carrot - the promise of loot, collective security, just generally respecting their allies - than they did the stick. There simply wasn't enough stick to go around. 7/

This comes out very clearly in the events running up to the Social War (the revolt of the Italian allies in 91). Part of - and this is a tweet-unfriendly complex issue, forgive my simplification - part of the reason for the revolt was that the balance of benefits...8/

...in the alliance system had shifted decisively towards Rome. The 'loot' income stream, which the allies shared, was being replaced by a 'tribute' income stream, which they had no part in. Moreover, a Roman program of land redistribution, the Gracchan reforms...9/