The word, "military" comes from "militis," which is Latin for "soldier. Throughout history, "military" has been used strictly to describe, soldiers, soldiering and land operations (and by extension, air operations as most modern air forces were born within armies). However, English is an evolving language and usage tends to change over time (e.g. "gay" today has more meanings than it did during the "Gay (18)90s"). While it is certainly true that "naval" and "military" were distinctly different at one time, usage in the last few decades has changed that. Thus, while it is still correct to make a distinction between the two, it is no longer incorrect not to.