Jehovah's Witnesses don't go to war. And who else is doing the preaching work like Jehovahs Witnesses?
I've debated this many times:
On War: There are 2 angles on this.
First one is the fact that Jehovah Witnesses are not unique on this. See http://en.wikipedia.org/wiki/Conscientious_objector
The second angle is that fact that war and/or armies are not necessarily bad. Jehovah blessed many armies and wars as long at the motivation was acceptable. Armies serve as protection on a national level in the same way police does on a local level. If a country is attacked by a foreign evil force, shouldn't there be any protection? I often offer the analogy:
If there was a city made up of only Jehovah Witnesses, and a large group of outsiders were on their way to rape, murder and rob this city, wouldn't these Jehovah Witnesses organize themselves and defend it? It is reasonable to think they would... This would be an army, and certainly this war would be justified. So the objection to serve in an army, shouldn't be the fact that it's army. You should instead object to a specific war if you don't agree with the reason behind it.
What about people of the same religion fighting on both sides?
Let's go back to our analogy. What if that group of invaders who were on their way to rape, murder and rob also called themselves Jehovah Witnesses?
Is it reasonable to say that:
a) Despite calling themselves JWs, they are not acting like it?
b) Do the residents still have the right to defend themselves?
Along these same lines, we can agree that catholicism as a whole does not endorse torture, murder and extermination. But what if many who were part of Hitler's army call themselves catholic?
a) Are they really catholic?
b) do we still have the right to defend ourselves?