There is the complication

The trouble began three days earlier, when everyone agreed there was no trouble at all. The expiry date arrives when the people who must carry a truce out of the hall discover that nobody has inherited the reason to keep carrying it. A lord may have sworn; the gate captain has to open the gate, the steward has to release the grain, and the rider who brings the order has to reach the next watch alive.

That is where a truce grows its hidden seams. The written promise may say nothing about a toll on the road, or whether a farmer can bring timber past a guarded bridge, or who pays for a horse taken during the fighting. Those questions still get answered, usually by the person standing nearest the gate. If that answer becomes a habit, people begin to plan around it; if the next captain calls the habit a favor, the truce has already narrowed, though no one has announced its end.

A peace that survives its makers can be more dangerous than one that breaks at once. The miller starts sending flour along the reopened road; the guard lets the carts through without asking for a second seal; the village stops hiding its winter stores in the woods. Then a new steward arrives and sees not a settled arrangement but a string of unpaid dues, unguarded goods, and permissions granted by someone who no longer has authority. He can restore the old practice. He can also charge for it.

There is the complication. Dependence can hold people together, because a stopped road hurts both sides; it can also give the side with the keys a quieter weapon than an army. A truce does not need to be broken to become a threat. It can remain perfectly in force while every ordinary act covered by it grows more difficult, until one party is paying for the name of peace and the other is collecting for its use.

So the careful person watches the handover, not the feast where the agreement was made. Who receives the keys, who keeps the account, and who is allowed to say that an old permission was never written down? Three small matters, all easily postponed; then the smallest one, the gate left shut for a single morning, becomes the explanation everyone had been waiting to give.