“四线作战"? No, at least 5 places - 1) Taiwan straight (100%, with Taiwan, US, Japan, Australia? Philippine?), 2) East Sea (10% with Japan/US), 3) Korean Peninsular (30% with S Korean, US), 4) South Board (50% with Indian), 5) South Sea (90% with American, Japan, Philippine?, Australia, New Zealand? NATO!?), and hopefully China can beat them all.