Anything that helps bring peace to humanity ought to be taught . I see no reason why religion should not encourage peace studies . The problem arises from the fact that every religion puts its own place above the rest of the others and not as equal . Early days education , high schools , colleges and universities are excellent places to learn about peace and its loving nature to all .
You can indeed love peace without believing in one God or many Gods . Also you can promote peace for the sake of humanity without belonging to any specific religion at all .To love and to work to achieve peace and oppose wars is a noble task that should be cherished by all man kind .

If there was ever any question as to whether an atheist can be a pacifast, let that question be laid to rest - we can, and many are. It's one of those qualities that can be found alongside some very high ethical standards integrated with firm iteals of integrity.

Most often the ethics of an athiest are much easier to explain, understand and adhere to, because they are based, more, on the logic associated with 'best' actions than are the morals developed over time by a changing religious dogma.

When an athiest judges s/he does so using subjective experience and can explain it without requiring a long term belief committment or the ability to read many ancient languages or the need to be infested with a spiritual being.

When an error occurs and is pointed out, it becomes much easier for the athiest to make adjustment as well. For the athiest has only their own meager experience and cognition to account for, while the very religious risk loosing face with a whole subculture, eternal life with their god and the loss of a belief that supports the weak of spirit.

It is a need, that many religiuos have, to defend one's dogma, that contradicts the idea of a religious people being pacifast. Fortunately there actually is one example that prevents this statement from being blanket - The Amish.

It just goes to show that pacifism can exist in a religious group, but it is obviouse extremely rare.