It's a 10 second blurb at the end of both episodes. If you blink you might miss it. They are shown not getting along at first.
Yeah, it's literally ten seconds. Human and alien girl walking along among others. Alien girl's backpack falls - presumably because human girl knocks it off Alien girl intentionally trips human girl in library (full of real books - some of which seem to have dewey decimal things on their spines) Close up of alien girl's face with tears. She's clearly not Romulan. Close up of girls (presumably) holding hands. I wasn't expecting Children of Mars to involve literal children. I'm having a hard time understanding how this ties in with Picard. Maybe the alien girl is an ex-borg? Maybe they have to be raised in a low-tech environment due to the trauma of assimilation?
It also appears that they both go to some kind of Academy since they are both wearing the same type of School Uniform. I thought at first it might have been an all girl school, but I think there might be a very quick shot of the back of a boy who is also wearing the uniform. I guess with such limited info we could speculate that the school is on Mars? Have we ever seen an alien race with that configuration of raised dots and brow ridges on their face? I suppose she could possibly be a human/alien offspring.
I've always assumed that the Kzinti were low-tech pirates, attacking defenseless Earth colonies in Alpha Centauri and other nearby worlds (maybe even Earth itself in the final war), because they weren't strong enough to fight against more established cultures, and they tended to be aggressive to pre-warp or new warp civilizations. But humanity had an ace up their sleeve (the Vulcans), and after a period of intermittent raiding, concession, negotiations, and raiding again, the Vulcans forced peace for humanity's sake and the sake of defenseless pre-warp cultures, and "negotiated" with battle cruisers and forced a treaty to disarm the Patriarchy and end their raids.
As a teenager, I devoured Larry Niven's Known Universe books and short stories. This was my introduction to the Kzinti. I didn't have access to TAS at the time, so I had no clue they popped up there. I've never really been a fan of this cross-over, however. What was the rationale for including them in TAS? Just that they hired Niven to write the episode? (The Slaver Weapon was based on a one of his short stories).
Thought a lot about that, and one way to reconcile it is have the Kzinti by not particularly more advanced than Earth, and also be a migratory species. Perhaps they tried to aggressively settle in the solar system a few times and got kicked out by Earth in each of those brush-fire wars.. It would explain why they already had a militarized starfleet by 2155.
If Sulu is being less than literal in his account of the events, it would stand to reason that he is spinning them in a way that ridicules and humiliates the Kzinti (rather than, say, flatters them) - yet so that he cannot simply be contradicted by pointing out contradictions. So his alternative facts probably ought to be nuances and interpretations, not outright lies. If he says "200 years ago", perhaps he's exaggerating to drive home the fact that the Kzinti were outclassed really long ago and have only fallen further behind in the meantime. It's not as if he could be belittling the passage of time instead, in terms of what we know of Trek pseudohistory - but finding a motivation for him to do so is also difficult. If he says "four wars", then probably there were four of something. "War" could be a derisive name for something less glorious, as in "you ah so bravely bravely fought four wars against our janitor", but the English language doesn't readily offer a way for "war" to be an understatement for something bigger or more serious, nor is there a good motivation for Sulu to understate here. If he says "fought with humankind", he might mean "fought against a vast coalition" or "fought against our girl scout space annex biannual field trip". The latter really makes more sense here: Earth at this stage should stand mostly alone, but OTOH omitting any reference to help Earth did have would make the Kzinti look like even bigger losers. But if it were the Vulcans who singed the Kzinti tails, why doesn't Sulu say so? Being beaten by vegetarians ought to enrage the cats the most, if that's Sulu's aim. Or is he already considering Spock his ace in the sleeve, the threat the Kzinti are constitutionally incapable of recognizing? Anyway, assuming that Sulu stretches the truth is generally workable. And deciding that this means the Kzinti mounted four really feeble attacks not quite that long ago is not impossible. The general gist of the scene is of Sulu mocking his opponents; sticking to a literal interpretation goes against that spirit. Timo Saloniemi
Basically they hired Niven to write an episode, as he was a popular "young gun" in the genre at the time. He gave them two teleplays, and both were rejected by DC Fontana as not right for Trek. Finally Roddenberry just told him to adapt The Soft Weapon into an episode. Of course he changed the characters - Nessus became Spock (thankfully the vegetarian thing worked) - but otherwise it is indeed the same story.
I’ve said this before and I stand by what I wrote: I take Sulu’s line to be the literal statement Niven meant when he wrote the episode. Two centuries before TAS, humanity (and humanity only) fought four wars (not skirmishes, not defenses from raids, not minor battles) with the Kzinti. People are welcome to take Sulu’s line out of context to justify how it fits into the whole Star Trek canon (so that I don’t get mistakenly labeled as someone who has ‘no imagination’) but IMHO it’s not necessary. Just like I don’t need an explanation as to why Kirk’s middle initial is R instead of T, or how Sarah April served on the first ship with warp drive, or why the Klingons’ look keeps changing. It’s canon, but it’s not in continuity, and that’s just fine and dandy.