[mr. tegu]

Originally Posted by HolyHandgernade

Spoiler!

Gandalf cannot simply appear anywhere he wants to be and apparently was not in the area when Smaug launched his surprise attack. He is not impervious to harm either, and attacking a dragon takes quite a bit of punch to accomplish. Gandalf suspects there are larger forces at play and is concerned that Smaug could be used as an agent of this darker force. Gandalf is trying to stir support for his belief in this new darker force, and helping the Dwarves recover their home would set up an effective shield should war come to the Northern part of Middle Earth, which it does.

Thanks! That makes sense.