Saw 1 sinkie post on FB to explain. Maciam ada logic but I dunno if facts are accurate.

If war happen, CCP will find nearest major USA military base to neutralise. This is at Japan. Then nearest logistics support is SG, which they also might KIV for boom boom pow.

If you read up on Japan strategy to control the Pacific during WW2, it is quite similar. Pearl Harbour pre-emptive strike was due to this but they screwed up big time.