The VSE is Covenant's vigilance for what he can really see, feel, etc. The need to maintain constant security over his physical form.
Ironically, for Covenant the Land is anethemic to the VSE, since his doubt and skepticism lead him to conclude until much later in the saga, that the Land is unreal.
Of course, the VSE became Covenant's obsession to the exclusion of everything else, and to some degree robbed him of his humanity. He became a slave to self-examination, to doubt, and so forth. It rendered him powerless to hope, to dream, to believe in something greater than his own limited world of his senses, until of course, later . . .
The Vow of Peace is similar too. Ironically it robbed the Lords of their ability to master the very Wards that would have led perhaps to a quicker end to the war. It required them to shrieve themselves of their drive and passion, to fear Earthpower for its destructive capacity, and thus limit themselves albeit for a very noble cause.
And of course, the Oath taken by the BG was also self limiting wasnt it? While in place it was all consuming, robbing the BG of their own humanity (can you really live for thousands of years without sleep and dreams and still be capable of human comprehension and understanding?) and when breached or broken, it left the BG without a purpose.
Fun to think about.
