Yes, bicycles are considered military vehicles. Many countries have used pedal power during world conflicts, such as the US, Japan, Germany, and Switzerland to name a few. Montague USA manufactures bikes for the US Military and Law Enforcement offices.
Dale Aylward's WWII Japanese Bicycle
Dale Aylward's British Airborne Bicycle
Peter Rebernig owns a few rare military bicycles. The first one is a a 1960 West German BUNDESWEHR bicycle from the German Army.
This is a 1945 Swiss Army Courier Bicycle.
1943 BSA British Folding Paratrooper Bicycle with Everest Carrier