When I was down in Ecuador, it seemed to me that socialism would work in a country like that or Venezuela where there is large untapped source of wealth and a majority of poor people. Letting foreign corporations in to develop the resources would only serve to enrich those in power and destroy the indigenous people's way of life. A socialist government developing the resources and redistributing the wealth could have great benefit to the poor and the country in general.
That is completely different than a country that doesn't have an undeveloped source of wealth such as oil. If the only source of wealth is invention and production, only capitalism will work. Whereas using socialism to redistribute wealth found in the ground can benefit a country, using socialism to redistribute wealth found in peoples pockets will destroy a country.