 The song was written on a Spanish guitar , and the melody lifted from a piece Bono composed in Ethiopia in 1985 to help teach children basic forms of hygiene . The lyrics contain an implicit criticism of the Reagan Administration , which backed two South American regimes that seized power during coup d <unk> and which provided financial support for the military regime in El Salvador . <unk> it has been interpreted as an examination of failures and contradictions in US foreign policy . 
