(Al Jazeera) Russia tight-lipped on Syrian demand of al-Assad for military bases. Quoting,

Russia has declined to comment on reports that Syria has demanded the return of Bashar al-Assad in return for allowing Moscow to maintain its military bases in the Middle Eastern country.

There is a traditional face-saving solution: Assad assassinated in Moscow by radicals recruited by the KGB or GRU from central Asia.  The assassins never know who they are actually working for. Following the accomplishment, the assassins themselves are liquidated.

Similar action could be facilitated with Assad first receiving asylum in northern Cyprus, where the survival record of Russian traitors is notably poor.

An alternative is the “unfortunate accident”, such as a fall down the stairs, or defenestration, but this requires coordination with Assad’s security detail.

And, of course, there is always Novichok.