Why does the military make some people who served in it for years really calloused and others not so much?

Several reasons come to mind.

We are not all the same. We each handle stress differently. So what effects me, may not effect you the same way.

We each do different jobs in different branches. Believe it or not, serving 20 years in one branch is not the same as serving it in another branch. And doing paperwork for 20 years is not the same as doing a combat job for 20 years.

And always remember this, the military is not always at fault. Many times people who are already jerks enlist. Then of course any negative actions they take in life will be blamed on the military which is wrong.

If you mean those who get out and seem disillusioned then that is always the nature of leaving a very organized command structure. there are also life long friendships made. The military is a frame of mind that doesn't exist in the outside world. there are also the disasters that men and women face being in the military. Families take a incredible toll and marriages fail or become stronger, children see their dads and now their moms infrequently being stationed elsewhere.

The civilian authorities who conduct misadventures called police actions and nation building forget these people need moral, family and health building themselves. They also for get to really thank the military the way they should with desire to carry through on engagements and to think before they commit. Most civilian authorities are cowards who don't mind sending someone for a concept or a ideology. In the military you don't need an ideology, you need command structure that believes in what it is doing and is allowed to do it thoroughly. The civilian authority is always frightened that the military will see through the politics and that that will affect the peoples will to sustain the politics behind conflicts.

I have to agree with Perro De Lava on this one. Everyone acts and re-acts differently. Training in the armed forces is the same for everyone. Of course, different branches of the military train differently, but ultimately....it's up to the individual.

I support our Troops....every branch.

Take a look at CNN Heroes.....There are people there that went through hell while serving our country, and came back, wanting to help others. Then there are others that could not deal with society. It really is about an individual, not the military. I do think, though, that the military could and SHOULD provide more services for our homeless and disabled vets.

because people react to situations very differently and no two military people have the same experience

People all respond different to there environment. Its all due to the Type of personality you have.