Nov 3rd 2010 8:05PM Eh. I admit my bias now by saying that I am a Horde through and through. That being said...
Jaina, while being a powerful magic user, is essentially just a young girl. She was given three options: fight and possibly kill the man she might love, help him destroy a city of innocent people, or walk away. While admittedly more mature than most I can understand her decision. Since then she willingly didn't side with her father mindlessly against the Horde, instead choosing the more difficult path and letting her father die. Again, I admit my bias towards the Horde, but this says to me that she learned her lesson about hard choices and walking away.
Uther, on the other hand, knew war. He knows death and destruction. He also is a PALADIN. His student is about to slaughter a town of people and he walks off. That is really pretty awful and honestly not a very great option for someone who was the first Knight of the Silver Hand. The right thing for Uther to do, not as a knight of the realm but as a Paladin of the Holy Light, is knock Arthas out, drag him back, and figure out what the bejeezus is wrong with the kid. I'm not sure how strong Arthas was as a Paladin but I'll bet not as strong as Uther, especially since the Prince was in the middle of one very bad fall. I mostly respect Uther, quite a bit actually, but this one act is a cheap and easy way out. Yes he winds up paying for it with his life which is really all he had left to give at this point but he, through inaction, allowed the Scourge to bring about an invasion by the Burning Legion, the defilement of the Sunwell, and the destruction of the World Tree.
Between Jaina and Uther they should have had no problem disabling Arthas until someone could find a better way. Yes, the army might have gotten more demoralized than it already was but walking away didn't work so well for that either.
Personally I hold the first official Paladin, leader of the Knights of the Silver Hand, and all around good guy a lot more responsible than the little girl who finally grew up afterward.
PS Right up until the Kirin Tor moved Dalaran up to Northrend I would have said it had a mystical significance where it was and could not be moved. Now...I guess mages just incinerate any insurance people who come to call. Or turn them into sheep. Who knows?