US military chief lauds Japan's record defense spending to counter China, North Korea

General Mark Milley encourages Japan to double defense spending over five years.
Milley cites need for improvements in cruise missile defense, warning systems, and air capabilities.
China's regional ambitions and aggression pose instability and danger.
North Korea's missile tests and nuclear aspirations add to regional tensions.
Strong US-Japan alliance and Japanese military seen as deterring war.