The article "Use Theocratic War Strategy" in the 1957 Watchtower (5/1 pp. 285-286) refers to the 1956 Watchtower (2/1 pp. 76-90) in the footnotes.
The 1956 Watchtower contains the study article "Cautious as Serpents Among Wolves" which spends fifty paragraphs discussing how we are to be cautious as serpents with many Bible examples. It uses the expression "war strategy" five times, and the word "strategy" fourteen times (including "war strategy") in the article. This was a positive endorsement of what has become known as theocratic strategy or warfare.