Hmmm. I distinctly remember the Goblins being the 2nd closest civ to me, and having the red ------ at embark. They must have signed a treaty sometime after my embark. Ah well, maybe if I build gem-encrusted gold furniture they'll decide they want it enough to declare war.
Once world gen stops, nothing really happens outside of your fortress. So no, a peace treaty wasn't signed after your fortress was established. The dwarves, even if they ever did start wars, wouldn't declare war against the goblins, because its just you creating problems. You can cause other civ's to declare war on you, but as mentioned the typical triggers for instigating a war don't occur with goblins.
I had peace with goblins once. It was really annoying considering it was a test of a minecart grinder. I got kobold ambushes and theives. I even got goblin snatchers. Never did I get a seige. I abandoned that fortress. Too bad, it was a savage biome just a short walk away from a dark fortress, but I failed to notice the peace before I embarked.
If I remeber, goblin peace treaties typically only last a few years before they re-declare war,
in world gen. I don't know what extent of world gen runs between fortresses (abandon in summer, your next embark is next spring),
probably none.
If word gen did run in this time, the goblins could theoretically redeclare war after 20-30 abandoned fortresses. But I must insist that world gen never runs between fortresses,
so this won't work.