before conquering uruguay portugal was united with spain and after its independence the relationship between portugal and spain was something more than friendly, something like a brotherly relationship. So there is no reason to be afraid of loss of contact between the states of Brazil.
Portugal enters Uruguay for the first time seriously in 1811 for fear of Spain being conquered by Napoleon.But it only really goes to war and conquers Uruguay in 1816 when its long-time ally Spain loses control of the colonia de la plata (Argentina+Chile+Uruguay) to maintain control of the rivers.
Uruguay became independent with the help of Argentina in 1828 (after the Brazilian War of Independence that lasted from 1821 to 1825) but in the agreement, uruguay becomes a buffer state and declares neutrality in relation to the rivers, thus ensuring Brazilian access. Brasil invades uruguay again in 1864 when uruguay is in a civil war and the pro brazilian ( pro neutrality) side has a chance of losing. Having the mission to install a government for neutrality (something that was supported by Argentina). they managed to do that in less than a year.
i doubt portugal wanted to ask permission every time it need to go to one of their states. Something that is done several times a year bringing resources, settlers, weapons etc. Especially the spain of this timeline that helped in the invasion of portugal and is in favor of napoleon.
It would be the same as surrendering to napoleon. When one nation needs authorization from another to communicate with its states , the nation it asks forthe permission is a vassal state in all but name.
the conquest of uruguay threatens buenos aires which is the heart of argentina. Preventing argentina from doing something out of the ordinary.
brazil and portugal wanted these regions because they were the most fertile in south america. they wanted as well the Mesopotamian region(very fertile as well)
the population of argentina in 1820 was 0.57 million people. Brazil in the same period was 4.58 million, considering that more Portuguese came to Brazil in this time line, I would put the population at about 4.6 million (Portugal had 3.29 million many who will immigrate to Brazil to escape Spain and Napoleon). The brazil of this timeline has the population and has the portuguese armed forces which for the americas is the same as having the napoleonic army.
it will not be full blowm , spain it is not a free state to make its choices is a french vassal , the overlord will use the spanish forces as it pleases. Spain is not going to take most of the army and sail to Brazil to defend Argentina (especially considering that ships is something that France is lacking and Spain has one of the only functional ones in Europe, so the only way to France allow this invasion is if it is a part of the invasion, this brings the British to war,and we know the result of battles between france and uk in the water)
they have fewer veterans, but a european force is much more trained than a colonial guard
Buenos Aires did not let Portugal conquer Uruguay, the nation was unable to prevent the conquest.
it's not going to be a war between spain and the colonies. Spain has the problems that I mentioned above and in relation to the colonies, what will Spain do to take troops out of cupa or mexico, leaving it to the us, uk or revolutionaries?It's not possible
the parts in yellow are habitable and the rest up to the late 20st century are impassable areas for an army, hence the importance of navigable rivers. if spain wants to move part of the chilean guard to argentina it has to do it by ships or literally lose most of the army because of attrition.
spain has a better situation at home but in the colonies the situation is not good the only positive so far is the fact that no mega revolution has taken place.the only revenge that i see would be to annex portugal. apart from that there is nothing that spain can do that would prevent a portuguese advance to the southern cone.And if by chance the annexation of Portugal would only create more reasons for the exiled Portuguese to want to steal more of the Spanish Empire
View attachment 737244