Does it make sense in RP for a house planet (Honshu) to be connected to uncontrolled space (Okinawa) via a gate and a lane without a border station or battleship? Is the only example besides Honshu really Denver, Colorado to Galileo? Not that that's the same, because Galileo does have Liberty Navy patrols.
To find the nearest example of this, we actually need look no further than the next trade lane.
From Honshu runs a lane to the Sigma-19 gate, and thence into the borderworlds, with no installations along the way save for Aomori. If Kusari cannot trust GMG to maintain peace in Okinawa and fears a threat to Honshu, how can they live with the instability in Sigma-19 (which is constantly assaulted by Outcasts and Corsairs) and not see that as a threat to their planet? Obviously, they put more faith in the GMG than some would credit...