The Murvick invasion has become too big of a problem for just two countries.
Provst, a well-known country in the north of Haal, is reputable for their peoples' ability to purify and manipulate water. They have been entrenched in a war with your county for what seems like centuries; your country has no clean water, and the Provstians refuse to give your people aid. It stems from the death of their beloved Crown Prince who, five years prior, died under suspicious circumstances when your dignitaries were invited to discuss country relations and recompense for services rendered. Since then, Provst has neglected to send any nobles to help with purifying water, leading to a war between the two countries. Provst is happy to continue the fighting until a new threat looms on their borders.
King Looen of Provst gives the gift of his daughter to your country's King/Crown Prince, along with promises of keeping your people alive with potable water. The trade is that your country's army, who is renown for their strength and numbers, assist Provst in fighting this new threat. The Murvicks, a race of creatures somewhere between elves and goblins, have become a bigger problem than you care to admit.
Your country wouldn't even think of this offer as more than a slap in the face, given how many of your citizens have died senselessly. The problem? Trouble looms at your borders as well, and one you are sure you won't be able to fight on your own. Nations from the south, east, and west have decided they want your land for their own, and your armies - although well-known - have suffered due to the lack of sanitary water. You accept the offer of the Provstian's sole princess, bound to you by an unbreakable promise: marriage.
Provst will send aid immediately, but what happens when they learn of attacks on their princess when she arrives? You don't know the culprit, and keeping the spoiled princess alive is a task that requires both your full-time commitment and attention. When these threats reach you, you have to wonder if it is a rebellion, another nation, or the Murvicks.