An imperialist power (AKA: Terf Islands) didn't liked a nation with independence (Expansion of education for the “common man”, use of foreign engineers and technicians for the developing of the local industry, manufacturing weapons, ships and first necessity items, a closed protected markets that started to export to their neighborhoods at lower cost than the British products, etc.)

They were an alternative experience of state construction in the new independent nations of the south.

So they manufactured the "Triple Alliance War", a genocide that destroyed most of the Paraguayan Male population, their industry and strengthened the subordination of the British allied nations (Brazil, Uruguay and Argentina).

They were real. And the imperialists want you to forget about it.

Source: León Pomer - "La Guerra del Paraguay: estado, política y negocios"

Pd: Lol at that Paraguayan oficial.