1) practice - An NCO usually has experiances a non-com doen't He/She has seen deployments and in several cases fire fights and can teach you lessons in survival that you cant get out of a book.
2) respect - An NCO gets his/her job accomplished by respecting his/her troops and knowing they are the best trained, and lead people that the NCO corps has got. The respect flows both ways without non-coms NCO's are ussless to carry out missions and with out NCO's Non-coms are leaderless. To fight in either situatin is to loose. 3) Order and disipline - An NCO's first responcibility is to the mission that supperiors have given him/her. He/she must insure the troops are displined enough and trained enough to accomplish that mission in some very dificult and dangerous situations and to have orders followed quickly with little or no thought that they are right or wrong because an order not followed could spell disaster to a unit and death to fellow members of a unit. When failure is not an option the orders must be given and followed quickly so the troops must know that their leaders (NCO's) know their business and have their wellfare in mind as well as the mission. Those are only 3 reasons for the respect but I think the biggest is because the NCO is intrusted to lead by example. An NCO should never tell troops to do a job or mission the NCO has never done or is unwilling to accomplish themselves. I might not like a mission but I must lead by example to insure the mission is accomplished and the troops under my charge are ready and trained to the best of my ability to insure their survival.