This is a principle that is uncontroversial, that the state's actions
   against citizens must be limited and subject to open and transparent
   processes, not by a consensus of people selected to form the consensus,
   and that the government itself is not infallible (exemplified by the
   omniscient US government thinking Snowden was on a Bolivian plane).
   Of course Assange is an Ecuadorian citizen, so if they wanted to, they
   could have him leave the embassy through temporary diplomatic status,
   particularly since he isn't accused of any crime by the British.
   Naturally this won't happen, as he is a bargaining chip in the current
   system.