消息人士：日本可能会考虑采用新的美国F-35隐形战机或对老旧战机进行升级，来弥补空中防御的漏洞。

Core Viewpoint - Japan is considering adopting new American F-35 stealth fighters or upgrading its aging aircraft to address gaps in its air defense capabilities [1] Group 1 - Japan's potential shift towards the F-35 stealth fighter indicates a strategic move to enhance its military capabilities [1] - The consideration of upgrading older aircraft suggests a dual approach to modernizing Japan's air defense [1]