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general::
Phrase(s): declare war against someone or something [and] declare war on someone or something
1. Lit. to formally announce that one will fight a war with someone or some country. • A group of countries declared war against the aggressor. 2. Fig. to announce a serious campaign against a type of person or a serious problem. • The president declared war against crime and criminals. • The pressure group declared war on waste.
McGrawhill's American Idioms And Phrasal Verbs