Edgy in a different way was the idea of the asylum, and the welcome, that Romulus gave to all comers–foreigners, criminals, and runaways–in finding citizens for his new town. There were positive aspects to this. In particular, it reflected Roman political culture’s extraordinary openness and willingness to incorporate outsiders, which set it apart from every other ancient Western society that we know. No ancient Greek city was remotely as incorporating as this; Athens in particular rigidly restricted access to citizenship. This is not a tribute to any ‘liberal’ temperament of the Romans in the modern sense of the word. They conquered broad swathes of territory in Europe and beyond, sometimes with terrible brutality; and they were often xenophobic and dismissive of people they called ‘barbarians.’ Yet, in a process unique in any pre-industrial empire, the inhabitants of those conquered territories, ‘provinces’ as Romans called them, were gradually given full Roman citizenship, and the legal rights and protections that went with it. … As one King of Macedon observed in the third century BCE, it was in this way [through inclusiveness] that ‘the Romans have enlarged their country.’
— Mary Beard, SPQR: A History of Ancient Rome, pp. 66-67. Compare “Benjamin Franklin’s Strategy to Make the US a Superpower Worked Once, Why Not Try It Again?” and “Why Thinking about China is the Key to a Free World.”