Katyia was the Revairian Princess who forged the great peace between the Seven Kingdoms, a hundred years previous to the game's timeline. An MC who declares at the introductions in week one that she intends to "follow in Katyia's footsteps" can expect to meddle in all the major conflicts that stand in the way of world peace. The major conflicts are introduced during week one.
What follows is mostly informed speculation.
Hise v Corval
Hise is a pirate nation, and Corval is a nation with enormous wealth and a massive merchant fleet. According to Hise!MC, the pirates consider raiding Corvali ships to be a kind of "honor sport". According to Zarad, Crown Prince Aamir is vocally in favor of declaring all-out war. According to everyone else, Aamir is a d-bag.
Wellin v Skalt
While the Wellish condsider themselves a moderate nation, they have strong religious faith and consider the Skalts to be unnatural heretics. Conservative members of the Wellin aristocracy may be in favor of attacking the Skaltic tries to "civilize" them. Lisle mentions in his week one event that he opposes this line of thinking.
Arland v Jiyel
While the two nations are not facing imminent war, Jasper believes that if diplomatic relations between them do not improve, things could deteriorate rapidly.
As implied by the Welcome Feast narration, and by Jaslen's gossip in week one, there are two factions in the Revaire delegation, and there is some underlying tension between them. During week four, an anonymous delegate helpfully points out that Revairians excel at murdering each other.