The Hobbit: An Unexpected Journey2012

Gandalf:
Of course I was going to tell you, I was waiting for this very chance. And really, I think you could trust that I know what I am doing.

Elrond:
Do you? That dragon has slept for 60 years. What will happen if your plan should fail? If you wake that beast...

Gandalf:
But if we succeed. If the Dwarves take back the mountain, our defenses in the East will be strengthened!

Elrond:
It is a dangerous move, Gandalf.

Gandalf:
It is also dangerous to do nothing or cut the throne of Erebor, it's Thorin's birthright. What is it you fear?

Elrond:
Have you forgotten? A strain of madness runs deep in that family. His grandfather lost his mind, his father succumbed to the same sickness. Can you swear Thorin Oakenshield will not also fall? Gandalf, these decisions do not rest with us alone. It is not up to you or me to redraw the map of Middle-earth.