Peace and justice by peaceable means.
That, to me, is the simplest definition of positive peace. I've struggled with this over the years and have read many complex definitions. I believe they can rightly be reduced to the above definition.
The imposed peace--Pax Romana, Pax Britannica, Pax Americana--are classic negative peace conditions, engendered a passive-aggressive response because they use brute force or the threat of it to enforce a false peace imposed by an imperial power. In reality, the subjects, those oppressed, invaded, occupied and threatened are plotting the overthrow and eviction of the empire.
Peace and justice by peaceable means, on the other hand, produces much more sustainable results. The desire for revenge is redacted from the palette of responses to positive peace. Of course this will prove to be sustainable more often and longer than negative peace.
Ah, but negative peace can produce an empire that lasts. True, but only so long as the brute force lasts. If that is a price the empire can pay in all its faces--blood, treasure and moral/ethical costs--then it can maintain such a 'peace.'
Of course positive peace requires maintenance too. Our human nature is such that we constantly push the margins of social norms when we are motivated by selfishness and greed. At that point our social norms are a reflection of the cumulative individual norms and the civil discourse we have about them. Maintaining worthy social norms--including the peaceful enforcement of those good norms--is an endless struggle against corruption and venality, which are a part of human nature just as surely as is altruism.(This is why positive peace is a systemic product and a systemic means of production of that product. Each subsystem--education, law enforcement, the economy, law writing and interpretation, the family, religion, governance, collective self-defense, conflict management and more--has its own output, which feeds into the sum of forces that produces war or peace, low-level war, unjust imposed peace of the empire, or peace and justice by peaceable means.
As individuals and as collectives we make the world more or less peaceful, more or less just, each day. Is that a burden or an opportunity?