Complex sentence: Another example of a "terra nullius" is Antarctica, none of which has yet been capable of supporting human habitation without supplies from outside, and its status as "terra nullius" is partly enforced by the Antarctic Treaty System.
Split into simpler sentences: Another example of a "terra nullius" is Antarctica, none of which has yet been capable of supporting human habitation without supplies from outside. Its status as "terra nullius" is partly enforced by the Antarctic Treaty System.