By the way there was a view in the past that the gate was closed to prevent people from entering Kinai from Togoku (eastern provinces), but recently another view has been plausible that it was closed to prevent the state of emergency which had occurred in the capital from spreading to Togoku.
なお、関を閉鎖するのは東国から畿内への侵入を防ぐためという見方が従来あったが、逆に中央で起きた非常事態の東国への波及を阻止する事が目的だったとする見解が近年では有力である。