Drill Sergeant Says
To put a simple spin on the classic party game Simon Says, have an adult adopt the role of Drill Sergeant and command the children to perform military-style activities such as jumping jacks and push-ups. If someone performs the action without hearing "Drill Sergeant Says," he is out of the game.
Hot Grenade
This activity transforms the classic Hot Potato game into a military exercise. Play music in the background and have the children pass a toy grenade between themselves. Whoever is left holding the toy grenade when the music stops is out of the game. For extra fun, try using a water balloon -- if you are playing outdoors.
Military Obstacle Course
Construct a simple obstacle course in your backyard or in a spacious room indoors. Use boxes, nets, cones and other objects to provide obstacles for the children to jump, crawl, run through and climb over. Time each run of the course and provide a prize for the winner.
Air Force Academy
Have the children make their own paper airplanes and decorate them using colored pencils. Once all children finish their planes, have them throw their creations from a marked line and see which plane has the longest flight.
Tactical Operations
Divide the children into teams. Scatter water balloons across the backyard to act as mines. Blindfold one soldier from each team at a time and have him try to cross the makeshift minefield without standing on a mine. Direct other players to give their teammates directions to help them across. The team to get the most players across safely wins.