I would say, They're threatening life, or threatening liberty. Liberty would be more of a political thing, not tied to the life part. So its an either/or sceneraio.
if I was going to get on the grammar, I would be reading it correctly and the correct way to read that bs orwellian line is:
Life and so on liberty and so on and the pursuit of all who threaten it. ellipses (...) are supposed to be read "and so on".
I would also add, that in the united states the only people that can legally have their liberties, and by virtue of situation MUST have their liberties impinged are the military and prisoners. No one else can even sign a contract to threaten their liberty. Its against the law. You could also argue that people of similar health disposition may live shorter in the navy as well. SO maybe give up a bit of life, a good chunk of liberty and pursue those who no-one but the uber paranoid feel threaten other's.
So in that scenario, I would say it is more of an if/then logic proposition, as opposed to either/or.