I rode bikes on a few military installations in my day and did not have to wear a helmet(early eighties). But being ordered to wear one is somewhat different from electively wearing one for a slow spin around the block.JMHO
I enlisted in '82 and retired under Bush II. Times and standards change. When I go through the gate now there is a sign directing you to use your "hands-free". I say this to say standards of military discipline change with the times. To proclaim Americans wearing bicycle helmets as the "Sissification of America" is just plain ignorant. Fight Obama on his policies not silly pictures. We can do better. I used to think so anyway.