Alliance or Strategy?

I never get royal weddings, the ones between empires and kingdoms.
It's always for the greater good that some poor unfortunate prince or princess gets married off to some unknown partner in an even more obscure corner of the world to strengthen ties between countries.
Bridges do that as well.
So how fair is it to let them go through with the wedding?
And, No, I'm not watching re-runs of Mulan 2.
It's just that it is such a fragile bond that hopes to bring greater prosperity to the two nations.
What if the marriage was to fail and end in divorce; what kind of repercussions would it trigger? A war, perhaps?

This is an odd, ancient topic to post about. But it did spark my curiosity while reading the announcement of our country's Shaikh Nasser's wedding to the daughter of the President of Dubai in UAE.

The old and powerful empires of the Orient and even many kingdoms and reigns around the globe, especially the British, have followed this tradition for centuries to the dismay of the unhappy silver-spoon-bestowed, royally bred child.

Ethics and scepticism aside, I do congratulate His Highness Shaikh Nasser on his 'joyous alliance and union' and wish him a bright future.
And heck, whoever he marries is très lucky- their kid is going to look amazingly gorgeous with a dad like that!