How would Vietnam be different if it had been colonized by the Spanish instead of the French?
I can't think of any great changes to Vietnamese society or culture brought by the French. French influence on Vietnam is highly exaggerated. To be honest, there's not a lot of French influence in Vienam besides some old buildings, a few words for things the French brought like butter, carrot, chocolate and some French food like pate and baguette.
If Spain colonised Vietnam instead, I don't see any difference except it would be much harder for them to hold power. Spain was a declining power by that time
How France colonised Vietnam: they did this through indirect rule - through a pro-French Vietnamese elite. Vietnam had a puppet king who was still ruling
How Spain usually colonised: They gave the power to the church and the priests act as the overlords. I don't see this system working for Vietnam.
Firstly Vietnam was a highly centralised state. It had a system of central administration, with set law and taxation system. It was a functioning nation state by the time the French came.
It would be hard for the Spanish to consolidate their power. First they would need to convert the local population to Catholicism first before they can use the church as a domination tool.
However it would be much better for Vietnam if the Spanish came instead. Spain was the enemy of the US, this means that there would be no Vietnam war as the US did not support Spain
::How would Vietnam be different if it had been colonized by the Spanish instead of the French?::
It's hard to see the Spain of the 1880s doing something like establishing control over Vietnam.
For that, the very late 1590s would have been better: in 1599 the Spanish tried to establish a protectorate over Cambodia. Let's say that they succeeded, and some years later a border conflict with the Restored Lê ensues, and Lê Vietnam is conquered.
Vietnam would not have been a protectorate with a puppet monarchy: the Spanish did not like to share power, especially not with native underlings that could very well end trying to recover independence.
So, Vietnam is decapitated, and the local institutions are destroyed: instead, a Captaincy-general is established, and proselytize hard to establish Catholicism as national religion in both regions, while also imposing Spanish as common language.
Talking about regions, the disparate former Cambodia and Vietnam probably would have been amalgamated: together with the destruction of the native institutions and imposition of Catholicism, Cambodia could very well been absorbed by this Vietnamese, Spanish-speaking culture.
Of course, efforts to conquer and assimilate this Spanish Indochina would have mean that effort to do the same in the Philippines would have decreased: would Spain choose the former over the later, and cede the Philippines to the Dutch or the British? Or the other way around?
What would do the weakened Ming, under Wanli, do against the Spanish? Would they be ignored? Wanli, during his later years, refused to rule: would the Spanish take the opportunity to try and nibble at China's southern borders?
Ming-Spanish War, or rather, Southern Ming-Spanish War?
What about the Manchu?
Maybe this question became old, but I found it interesting. Many people told about how Vietnam would look like, and they think that we could be something similar to Phillipines. No. I can sure that. Why? Because Philippines had no centralized state before the Spanish came, but Vietnam had, since a very long time ago. The first independece Vietnamese kingdom was founded in the 6th century AC. It was influenced by China, and the same for all other dynasties after them. Vietnamese belief system based on the three pillars: Buddhism, Taoism and Confucianism. While Confucianism was an ideology more than a religion, the two other were so common. In nearly every Vietnamese villages, you can find Buddhism temples, you can find tutelaries of gods and heroes (not God). And most Vietnamese follow ancestor veneration and/or other folk religions like "worship of Mothers". So much like China, huh? If those Spanish wanted to spreading their regime by Christians, so they must defeat all of these things first, or at least, minimize them. Absolutely impossible. One more reason, Vietnamese was the official language of Vietnam before the French invasion. So they didn't have a need about a foreign tool for domestic communication like Filippino. After all, my answer is not much than today. In the terms of architecture, borrowed words and cuisine maybe be different, but in another parts, Vietnam would still like which you see today.