I can't speak for before I came back. Best of my knowledge, Cathay's had Ahael through 3 Aenilian rulers now. So perhaps I was lead to believe it happened much longer ago than is true. Or perhaps your timeline's off. Dunno, doesn't change things a whole lot.
Cathay took Ahael under Brian to prove to Xarnelf that they were serious about being pissed about his moving through Colasan to attack Ohnar West after they denied passage rights. That was basically what caused Xarnelf to step down (Cathay's demand for peace), which caused Rekhyt to be elected.
As for Zonasa, I thought they were doing ok until that last ill-advised suicide run on Talex. We were all set waiting to pounce on Larmebsi with them and likely pick off Arcaea a bit piecemeal (expedite their arrival with a TO), and they turned toward Talex instead- because their nobles were complaining about wanting to attack a city. 
But judging by what people here are saying, their military's been a mess for quite some time.
Zonasa's military before the most recent war was the joke of the Far East. They spent several (RL) years as an openly "pacifist" realm, and generally made gains after others did all the hard work. That's one of the reasons it was such a big surprise that they proved decisive in this war. No one in Arcaea was expecting it, as the last time we'd fought, Zonasa had been pinned down and beaten without much difficulty.
And while I'm grateful for them propping Aenilia up for what appears to be the duration of the entire war, it was a situation that our realm should never have gotten themselves into, and Zonasa, honestly, should not have felt obligated to participate in. General feeling in the realm (including mine IC) is pretty much just that. Zonasa did the best that they could, and better than we ever did, and we're much obliged. But then, like I said, there's not much chatter in the realm period, so who knows.
Zonasa's been wanting an excuse to fight Arcaea since the last conflict (see above), and Erandi decided to take the legalistic "despite not agreeing with anything Xarnelf did, we have an alliance" view to allow Zonasa to fight. Kindara was the real surprise, which I believe mostly ended up being a "we want a war" decision, as they were even more unhappy with Xarnelf's actions than Zonasa was.
Regarding realms and active diplomacy, that was the main basis for my diplomatic rankings. Zonasa, Kindara, and Aenilia have a fairly solid defensive alliance, though I doubt any of them will march for the other in an aggressive war unless it has good justifications. Arcaea and Ohnar West have a fairly good alliance, but Ohnar West is too battered to do much more now, and has internal issues that keep it from being effective in the slightest (and will cause all kinds of fun in the near future). Cathay just alienated their former allies in Aenilia (which was a fairly big surprise, as that
was an "allies forever" alliance), and by extension made Zonasa and Kindara somewhat unhappy. Everyone knows what they did to C'thonia, and
that combined with their reluctance to actually send troops to fight (they took Ahael against effectively no resistance) has severely weakened their alliance with Arcaea and to a lesser extent Ohnar West.
C'thonia has, effectively, only Arcaea for allies but a variety of factors keep Arcaea from being able to assist them, and they've managed to annoy all of their allies.
Arcachon
had allies in Aenilia, but they've just been isolated by the recent peace terms, and Arcachon's torture and harsher, borderline-Order of the Hawk violation looting has made a number of other realms who might have considered assisting them extremely unhappy.
Arcaea and Kindara may well end up allies again. There's a lot of people who used to be in Arcaea or have reason to like it in Kindara, and Kindara
is named after Arcaea's Queen for a reason. That will likely remain a weaker alliance than, say, their alliance with Zonasa.
I expect Arcaea to remain on unfriendly terms with Zonasa, and either realm will probably jump on an opportunity to fight if they think they can do so without being pummeled by the rest of the continent. I really have no idea what is going to happen with Aenilia.
