I’m sure he just wanted to test all (all) the food first to make sure his population doesn’t get poisoned; very commendable, really. Not everyone is a villain, you know!
I just re-watched all the first 14 Bond movies, and there are apparently satellites that can track all the subs, so we’re good 😊👌 Also, you can just reprogram the missiles to blow up the other subs — just steal the launch codes, easy peasy 👍 Check mate, Kim! 💥🚀
Side note: many (or, indeed, most) of the films did not age well 😣 I’m not proud of how little of the misogyny, borderline rape-y, no-consent, belittling of women stuff I failed to notice as a kid (patents’ fault) and adolescent (my fault); it starts to get a bit better around the end of the Moore era, and I’m now getting ready for the Dalton era. It will be interesting to see the newer films with this fresh context of the old ones, and I’ve never seen the two newest ones, which I think were supposed to address all of these issues.
Secondary side note: so far, the best ones (IMHO, YMMV) have been For Your Eyes Only, Octopussy, A View To A Kill.