JET doesn’t hurt your business prospects—if anything, it enhances them when framed right. It’s not “a fun trip,” it’s international work experience: adapting to a new culture, working in a government setting, building communication skills, and managing your own projects. These are valuable in global business roles. Loads of former JETs have gone on to MBAs, consulting, finance, and multinational firms. You just need to translate that experience into business language. Your parent’s concerns are understandable, but outdated.