Hidden Within the Ritarikari

The Ritarikari
The reigning monarchy of Magic Users in Europe for the past several generations, the current leader of the Supernatural Union. The Vampire Elite
The monarchy ruling America's vampires under the guise of democracy, the only faction yet to join the Supernatural Union. For generations, animosity has plagued these kingdoms, constantly on the brink of war and in need for peace.
Until an arrangement was proposed: A marriage between the Ritarikaran Princess and the Vampire Prince.
The problem that remains is that arranged marriages are a thing of the past.
If the marriage is agreed upon, the Ritarikari will become the most powerful entity in the world, with fearful allies.
If not, the power struggle between these two kingdoms will hit a fever pitch and cost countless lives. It sounds like the choice should be loud and clear, doesn't it?
So why can't I make the right one?