The CR attack the KNF, they aren't going to be best buddies.
How you could have a temporary cease-fire with your practically mortal enemies seems even more silly than the battle with the KNF.
You jeprodised your alliance with Kusari to help your enemy. That's like getting mugged and stabbing your friend, to help the mugger.
The CR were told to stay out of Kusari for 7 days and violated that.
The CR attacked Kusari Naval Force vessels, in Kusari.
That's like the [LN] flying into Bretonia, after being told not to, shooting some BAF and allying with Kusari against Bretonia.
You just basically declared war on Kusari.