Board Thread:Skyrim/@comment-109.108.7.9-20150406094840/@comment-50.36.122.95-20170226174126

The Thalmor fear a lot of things. They're paranoid, it's what they do.

Obviously, they don't ADMIT to being afraid. But they are. The Greybeards  will use their Voice to defend themselves. Therefore,  anyone attacking them better have enough suckers in the back lines to shoot the Greybeards, because all their close-in fighters are gonna get icecubed, flash-frozen, crisped with open flames, drained, disarmed, and generally blasted around. Because Greybeards don't have Dragonborn-like limits on Shouting. They just shout. And shout. And shout.

So since we've established that Greybeards will defend themselves, and know that they are ultra-deadly, the Thalmor fear them. They fear even more the power of the Greybeards to rally all of Skyrim. Every Nord respects, and, if it came to it, would obey the Greybeards.