(My thoughts and opinion and nothing else here – at a point in time. I reserve the right to update and adjust.)
To aim for world peace in the sense that all people can live harmoniously and at the same time be happy in a state of peace is a noble goal and dream. To endeavor to get to such a place is in some aspects are counter productive. This is due in part to the personality and psychological differences among people. In order for social, political, and any other form of peace, the population would have to be sanitized or altered in a way that is not human or inhuman. Some types of psychology would not be congruent with any structure to establish and maintain this. Some must be oppressed while others have impunity to achieve peace.
Where is the most agreeable common denominator to get close to peace where humanity is a society in safety and lacks oppression? While at the same time not requiring or forcing a type of person to abandon themself for peace.
Violence is not the answer, nor oppression and not elimination of others or the rights of any people. This in itself is a barrier as some personalities and psychologies have these as fundamental components.
The issue is complex beyond one academic subject or group. It is as diverse and varied as the people it encompasses adding in the factors of time and environment, etc.
Personally I hope with every part of my being, soul and spirit that humanity can come as close to peace as we have the ability to transcend to.