Peace depends on political decisions and economic circumstances. However, scientists and engineers hold a key position, not only in the development of knowledge and technology, but also regarding the possibility of war. Any discovery can be a contribution to the evolution of humanity or to its self-destruction, but the point is not the research or the discovery. Crucial is the ethics of scientific research and its application. We need to realize the profound meaning of life on Earth. Then can ethical consciousness increase and war will cease to be an option in human relationships.