To me, Dignity and Justice are encompassing principles that can be construed to cover most of what we desire in forming and implementing modern nation states. But in the current context of the United States as HyperPower pursuing global hegemony through war and Imperial rule, specifying "Peace" as an objective and a foundational principle is more and more desirable.
We may come to question the advisability of any nation-state in the modern world, but the default position -- absent nation-states -- would have to be either World Empire (which is the direction we're going), or tribal units, which is the direction I would prefer, though with many caveats.
Some random notes:
I am in favor of abolishing the states and substituting semi-autonomous regional governments, for the simple reason that states have become as rotten and corrupt as the Federal government, in fact, they probably started out that way. There are far too many statelets on the East Coast that could be more practically governed as a unit. There is a serious mismatch between the interests of various regions of the country and some of the states have internal mismatches between the interests, populations, and geography of one sector versus another. Break them up, reform them into affinity regions.
Autonomy is important. Direction from the Capital is only feasible with a unified polity, and the United States has never been that. Expansion merely disperses and institutionalizes inherent division. Instead, try for internal unification within the regional polities.
With regional autonomy, ironically, the national assembly can become an Imperial state, but one with strictly limited powers. In other words, the urge to empire, which appears to be deeply ingrained in the American psyche, can be expressed in a national government which ostensibly rules its autonomous regions (think parts of post Maoist China) with all the pomp and circumstance required, but which is purposely benign.
In fact, the national government does not "rule" so much as fulfill the mutual interests of the peoples of the regions.
With Peace as a foundational principle, the nation, much like China, does not engage in armed conflict abroad, and strictly limits armed domestic action. Yes, we have to think about domestic police action, potentials for armed rebellion and so on.
Dignity and Justice are principles that serve as brakes on the predatory interests and intentions of some, generally small, proportion of any population, and sometimes the predators among us become dangers to themselves and others. Their control becomes an interest of the People and the State, but that interest may have to be backed up with force. Predators do not generally yield willingly.
Dignity and Justice encompass more than Law; they are foundational principles of the social contract. They are fundamental principles of a desirable economic and social condition as well as legal principles. One should not separate Law from economic and social justice.
How they are expressed may be different from region to region, and the national expression may be different still.
To be continued...