Here are some points from the link in my OP.
Types of Pacifism
Absolute pacifism
An absolute pacifist believes that it is never right to take part in war, even in self-defence. They think that the value of human life is so high that nothing can justify killing a person deliberately.
Conditional pacifism
Conditional pacifists are against war and violence in principle, but they accept that there may be circumstances when war will be less bad than the alternative.
Selective pacifism
Other pacifists believe that it is a matter of degree, and only oppose wars involving weapons of mass destruction
Active pacifism
Pacifists are heavily involved in political activity to promote peace, and to argue against particular wars.
JWs are Absolute pacifists in so far as they view the deliberate taking of a life to be culpable even in self-defence.
It is this position that I think is unethical. Pacifism is a "counsel of perfection".