Setup your tent, and then sleep high up in a tree, ever watchful. When the bad guy comes for you in your tent, you can drop down on him from above. SURPRISE!!!

I have tried both, and in a hammock I had thought that I was easily approachable and visible. Unless I am sleeping on bare ground in some advantageous location, which is usual for me, I prefer a tent. Unless you are being stalked, a person can't tell exactly how many are in there with you, and there is no determining exactly where your head is.
Exit from a tent can be a surprise explosive effect through the wall with quick long downward slice with a sharp knife, if need be for some reason, and charging the guy. But then you don't know how many of them there are either. Just feeling like meeting the threat head-on can send contrary vibes to a curious would-be destructive black bear, but probably not a Grizzly.
A few thoughts:
trip wire, perimeter alarms, pepperspray, firearm, camo, light sleeping habits, loyal dog companion, travel buddy and two separate sleeping arrangements, etc.