One, the resolution or agreement may hold, but may only be one of many sub-conflicts in a wider and deeper systemic conflict among all the stakeholders. So, for example, a dictator may be deposed, but another conflict erupts over the same policing practices still be executed by the next government. Hello, Egypt.
Two, the agreement is a steppingstone to the next negotiation, the next subconflict. For example, an imprisoned oppositional leader may be released, paving the way toward the next round of talks about one person, one vote. That was what happened in South Africa.
Three, some parties not necessarily invited to the original talks that led to the original accord may spoil the agreement by extremely destructive action. This is what happened to the Oslo Process between Israel and Palestine; moderate Israelis and moderate Palestinian Liberation Organization leaders never invited either Israeli settlers nor Hamas--the more difficult radicals on each side--but chose to negotiate a successful peace accord in 1995 that was met with much jubilation for a minute, and then suicide bombers and an assassin by Hamas and a rightwing Israeli, respectively. The process began to unwind and eventually Ariel Sharon finished it entirely with his provocative visit to the the al-Aqsa mosque/Temple Mount on 28 September 2000, triggering the Second Intifada.
Four, all parties make an agreement that is almost immediately broken. This is often because the parties are pressured externally to sign something and do so to satisfy the external party, often a sponsor of some sort, frequently with money and arms, but the parties have no real intention of honoring the agreement. Think Somalia.
Five, the agreement emboldens one or more parties to view any gain as an invitation to escalate in order to solidify and enhance gains. When the Tea Party won significant gains in the 2010 mid-term elections they essentially hijacked the Republican party and imposed their jingoism, xenophobia, and misogynistic views on the receptive party leadership, turning the sequence into more destruction and backfiring on the Rs.
Six, a power-over resolution is reached in a power-over fashion and all others go into passive mode until they can become aggressive again. Anytime you get that outcome it is only a matter of time until the conflict re-emerges, sometimes hotter than ever. From the Peloponnesian War/Athenian genocidal invasion of the Isle of Melos in 416 BC, to the Treaty of Versailles/Nazis, those are harsh lessons.
For a nonviolent campaign to truly succeed (and when it does, it is much less likely to fall prey to the worst of these pitfalls, since it doesn't wage conflict destructively) it must carry on its work long after the victory or that victory will be quite temporary. This argues in some ways for a strong cultural connectivity on the one hand--keeping all networks in order--and professionalization on the other--those who give and give and give toward the agreement need to be replaced by those who make it their career to keep the agreement sustainable and healthy.
So win, party, play some horseshoes, and take a long vacation, but come back to continue the work for peace, environmental protection, and justice for all. It's a life, not a single campaign. The long haul is the only real stable path.
Kriesberg, Louis, & Dayton, Bruce W. (2012). Constructive conflicts: From escalation to resolution. (4th ed.) Lanham, MD: Rowman & Littlefield.