Asia's security system is dominated and sponsored by the US, which maintains several regional defense agreements and formal alliances with Japan, South Korea, the Philippines, Thailand and Australia. These are supplemented by a security partnership with Singapore and by evolving relationships with Vietnam, Malaysia Indonesia and India. So China's sense of insecurity is not paranoia, it is really ringed by US allies. Quite rationally, China is determined to dilute the US's grip on security in its neighborhood *).
*) China's Asian Dream by Tom Miller