The U.S. often extradites non-US nationals [0], even ones that have never been to the U.S. in their entire lives [1].

[0] https://en.wikipedia.org/wiki/NatWest_Three [1] https://en.wikipedia.org/wiki/Gary_McKinnon

Citizenship has no relationship to extradition.

It depends on the extradition treaty and the delivering country's law. Technically the US doesn't extradite people to the US, other states extradite people to the US upon their request in accordance to an extradition treaty.

The UK courts are still yet to decide whether there is a legal basis to extradite Assange. For example, the extradition of Lauri Love was denied by the court, which was also for computer related crimes allegedly carried out outside of US territory.

Various international legal frameworks and agreements.

I want to know too, specifically.