Atheism, correctly understood as the absence of theism, sure beats the alternative. But no, it is hardly the foundation for peace - or for anything really.
Science, however, is something else entirely. The findings of psychology, anthropology and sociology can go a long way towards facilitating the spread and effective application of solid ethics.
IMO, that is the only true answer to your question. The foundation for peace in this age, as in any other, comes from ethics, which is sometimes helped by religion and sometimes harmed by it.
In this age, specifically, applying and spreading ethics translates into denouncing the dangers of nationalism, spreading awareness of the need for bridging social and economic disparities, and accepting the dire need of keeping population levels manageable. We have reached the point where even attempting to have effective education and political representation has become quite the challenge.