Maybe the local governors, viceroys, leadership see Spain losing a major European war or feel they are getting short changed somehow
They throw off the Spanish and go from there.
If it's in the 16th or 17th century when this happensI can definitely see Spain making a go at reconquering the rebellious colonies.
Then I guess I have an inverse question. How long could Spain hold on to its's colonies. It seems like long-term it just won't happenIt would be difficult.
Spain screwed itself in the 18th century when it decided to become more involved in the colonies. Before then, Spain had been taking a mostly hands-off approach for years. Because the Peninsulares (Spanish-born whites) weren't very common, the Criollos (People of Spanish descent) were among the highest rungs of Colonial society. Then in the 18th century more Peninsulares flooded into the colonies and the local Criollos' power waned as positions of prestige often going to the newcomers. This caused considerable resentment.
But this wasn't enough. The reason independence occurred was that Napoleon invaded Spain. Revolutionaries used the vacuum of authority to advance their cause. But even then, a large number of Latin Americans opposed independence, especially in modern day Bolivia/Peru.
Then I guess I have an inverse question. How long could Spain hold on to its's colonies. It seems like long-term it just won't happen
Assuming no Peninsular War, I think you could have Spain keep the majority of their colonies indefinitely, actually, assuming it's able to reform.
One idea I've had is for the Aralda Plan, of setting up autonomous kingdoms, to be accepted, and then eventually see the kingdoms decentralize from the Spanish central authority to the point that they are virtually independent.
Then I guess I have an inverse question. How long could Spain hold on to its's colonies. It seems like long-term it just won't happen
The what plan? I've never heard of this before.