Universally mandating peace sounds like a recipe for failure.

The core problem with world peace is that every culture is different and disagrees on what is ethically correct. The drinking age is different everywhere.

Trying to generalize universal rules over everyone everywhere seems like a waste of time.

Use technology to improve quality of living and access to basic rights (food, clothing, shelter, medical care, etc.) and see how quickly crime rates drop. Employing a universal law to control everyone in a certain direction while still allowing people to be homeless will never work or change anything.