However you might want to classify it (and this is certainly not the only way to speak of the problem), it is this: the divorce of God from Nature, of Nature from Man, of Man from God. Or, Man's amnesia as to his status and purpose in the world. Or, a severence of the intellective faculty from the informing Logos. All healthy societies maintain and pass down such things (Tradition, in all its manifestations - even Nihilism); the West gave it up, allowed itself to be mislead, and began to descend.
We see no inherent worth in anything, because we believe in nothing in which there could be "inherent worth"; a passive Nihilism suffuses every single idea, ideal, and movement generated by the West, principally because the West is founded upon an interpretation of reality which has no room for eternal qualities such as honour, justice, truth, or decency - while these things are occasionally entertained, this can only be done for sentimental reasons; without these things being known as the eternal qualities they are, they are seen to be as ephemeral as anything else, if not even more so. Civilisation crumbles as a result, except we're bringing a large portion of the planet down with us, this time.
To put this in a less metaphysical, more psychological context: we have severed ourselves from the world in which we live, in a mad bid to proclaim a false sense of individuality, of independence. In order to make ourselves distinct, we have made the world "other", and we truly treat it as such: its resources are ours to take, its systems ours to meddle with, its death no concern of ours (we can just "move planet", or some such fantasy). Beyond the exploitation of the planet, there is an almost universal personal alienation: in making the distinction between what is "us" or "ours" and what is "other", we reduce ourselves to a certain range. This constriction leads to a fundamental cognitive dissonance, as consciousness recognises its identity with all things, the mind seeking only to support itself. We know, at one and the same time, that all things are interdependent, that there is nothing that does not rely on multiple others, and yet we wish to consider ourselves to be above such limitations - our desires conflict with our knowledge, and internal conflict results, leading to apathy, despair, wanton behaviour, etc.
There are a large number of other things which might be considered "enemy", but I believe it is best summed up in the current paradigm and its associated mental illnesses (being trapped in the mind, dissociation between self and world, ignorance of consciousness, etc.).
Is not democracy all about "I"? Shouldn't human endeavour be about "it"? Where has this bizarre self-importance come from, but the negation of all that might hold meaning higher than that of the appeasement of the ego?