Are we all criminals?

I am taking a class about International Law and Human Rights. This is a factinating questions that mix ethics, science, philosophy, law, etc. I will share with you some open questions that I am searching for good answers.
One fundamental HR (human right) is the right of life. I read an example of a person starving in an island, a sailor stopped in the island and leaves the hungry to die even if there was enough food for both of them. The sailor is responsible for the death of the man by his inaction; this death is in fact no different than stangling him, maybe it is more cruel.
We all know about the situation of Darfur. Are we criminals?