Simplify the following text for a Grade 12 native English-speaking person.
Original: Western commentators accused the Russians of keeping Spandau prison in operation chiefly as a center for Soviet spying , as they had an excuse to drive into western Berlin , and the soldiers often looked out over the city instead of into the prison grounds .
Simplified: Western commentators accused the Russians of keeping Spandau prison in operation chiefly as a center for Soviet espionage operations .