Orwell concludes that foreign authorities have power by virtue of their military might and power, but they will never be liked by the people they oppress.  He realizes that his position seems secure because he has a gun, but that none of the people in the country like him, and that he is in fact quite vulnerable.  If the mob moves against him (and remember that Orwell, as a member of the British military, is a symbol of Britain), he will be killed regardless of his arms.  Orwell realizes that his position and his power, like those of England, are tenuous.