Comment by mullingitover

Germany, Japan, the UK and the US (among others) all did things in WWII that count as terrorism, and no, the term isn't useless. The textbook definition, "the use of violence and intimidation in the pursuit of political aims" is exactly what was happening in the war, although I would add the caveat that it's violence and intimidation against civilians. Using violence and intimidation against enemy troops is just regular warfare.