what exactly defines military wristwatches?
Here are two examples of standard issue military watch in the G10 style. One from CWC and one from the Marathon Watch Company. Both watch companies make standard issue watches for the military in both the US and Europe. CWC (Cabot Watch Company) have been supplying watches to the British military for over 30 years, and replaced the previous Hamilton (UK) watch. Even today the CWC G10 watches are issued to British servicemen, and continue to be the watch of choice for the Ministry of Defence in the United Kingdom.