National Security

Would it be reasonable to identify companies that have either become so large or so entrenched in a specific domain that their failure could jeopardize our economy in a significant way? Could those companies then be restructured and or possibly split up in ways that mitigate the damage their failure could create? Could this be considered a matter of national security?

I know it sounds harsh but don't we do this in monopoly cases for the good of the public? (The Breakup of AT&T)

I'd be interested in hearing other peoples thoughts on the matter.