by 1913 Argentina was the richest country in South America and among the richest in the world, well Beyond France or Italy and on par with Germany, maybe even more. The decline of international trade and the political instability brought by the wars slowed down the amazing growth and locked Argentina in a cycle of political killings, dictatorships, boom and bursts. Without the wars, or with far shorter ones, could Argentina have mantained its wealth? will there be a war with Brazil, can the naval race continue? tell me what you think
The wealth of Argentina was not based on a self-sustaining engine though. It was based on an engine very dependent on outside factors.
Further, the state of education in Argentina was much poorer than in countries like Canada and Australia, which in 1900 appeared similar in many respects - right down the the vulnerable economies.
Poorer education in 1900 meant worse educated (or just less) professionals in 1930 than Canada or Australia and poorer education in 1900 meant worse educated leaders in the 1940-1960 period. And a weaker educated class and weaker leadership meant that Argentina didn't handle the challenges of the 20th Century as well as Canada or Australia did, so that translates directly into lower economic growth.
One can propose that the Great Depression might be avoided, or the OPEC embargo avoided, or the Falklands War be avoided. But one still would not address the fundamental area of relative weakness.
So IMO, the way for Argentina to perform better is not to avoid any one crisis, it is to go crazy for education as early as possible so that it closes the gap from their OTL level to the level that Denmark had reached by that point in OTL. Probably the simplest way to achieve this would be to have Argentina somehow avoid the civil wars between the provinces and Buenos Aires, meaning less is wasted in war and there's time for better education systems to grow naturally. That's a 19th Century PoD of course...
In the 20th Century, though, it's not unrealistic to have a crusading education reform movement such as that which produced the revolution in education during the twilight years of the Tsarist empire.
Even so, if the PoD is in 1900, I'd still predict that Argentina would flag during the alt-Peronist era, as the generation who had been educated before 1900 would still be deficient compared to later generations.
So I don't see how Argentina can avoid flagging in relative terms in the mid-Century without a second PoD. But they would be well positioned to gain ground in the last third of the 20th Century, perhaps seeing Argentina emerge as one of the top 10 economies in the world by the start of the 21st Century.
EDIT: Why would Britain put the war at Europe at risk just for a few lousy islands down in the south Atlantic that are nearly empty of people and, as far as they know, barren of resources?
Because the Falklands, along with Panama, is one of the key points controlling traffic between the Atlantic and the Pacific.
Controlling sea lanes is THE main resource for the British Empire.
Considering that the UK in WW2 can re-orient trade to other food producers like the US, Brazil, Canada (if Canada mobilized for war less) and Australia (if Australia mobilized for war less) at the cost of winning WW2 slower, it has to be in very desperate straits to consider giving the Falklands up to keep access to Argentine food.
Also, the Falklands were a very profitable colony for its size. Wool may not be big business now, but up until the collapse of the Soviet Union, is surely was. (Though the Falkland Islands wool industry is now making a profit again, which I never thought I'd see.) And back during WW2, it still had a big part in the whaling industry in the South Atlantic, so it was hardly "barren of resources" even if you ignore their extreme strategic value.
fasquardon