Thanks for asking !

I'll take more time tomorrow to answer in more depth(, even if only for me[, edit : probably not in the end, unless you're willing to have a discussion on this topic, i'd prefer to receive counter-arguments or engage in a conversation before developing this]), but for now i can quickly say that this set of rules/conditions won't be defined by a single person(, much less myself), as i see it it would take at least 25 years to build, and 5 years before the first (theoretical )experimentations. It'd be, after all, one of the most important thing that humanity could do.
This disapproval of other values can easily be solved through propaganda, we naturally aspire to peace and thinking that our side is better than the other doesn't imply we need to wage war against the "inferior ideologies", even for their own good, we should aim to change them only through the proximity of our example(, if they accept such proximity).
An obstacle i can see is our leaders, they'll think that they have to act for more supremacy while they still have time(, or continue with neo-colonialism to prolong it), and may honestly believe that the pax americana is desirable, or at least preferable to the alternative of an "anarchic" world. They won't immediately believe that we could make rules that can't be broken, such that "showing kindess" won't turn up against us in the end.
Among many other goals behind the experimentation of such rules, we'll have to think of every possible way to break these rules/conditions, and devise the most effective counter-measures ever thought of, i don't see any other way. A world army is an example of condition(, ~only used for humanitarian reasons), and has the advantage of pointing out the need to have trust in such set of rules/conditions, including the promise to be allowed as much diversity as possible(, as long as it doesn't break the unity).
The fear of a tyrannical world government forbidding diversity is also a reason for why such set of rules shouldn't be able to be corrupted, such decision shouldn't be taken lightly anyway, 25 years of preparation&testing seems long but may be too short, yet i don't see a better way, and the status quo of states fearing for their security isn't desirable(, i mean, i don't think you realize how many wars&destruction we caused, in the name of our vaguely defined interests or whatever, we could do better if we want to( let go of hegemony)).
If we ever plan to be an interplanetary species then it'd be great to have solved the problem of war without uniformity/hegemony before that.
There're certainly other problems to tackle, do you have one in mind ?