"Geez Louise, all this talk about a despicable deserter. To me Don was just a poor mistreated farm boy who joined the army to get away from home and ended up in an immoral and illegal "police action" by our government in Korea. He didn't hurt anybody when he switched dog tags."

Then the writers have done a great job...they've given viewers a reason to be sympathetic to a character that has done some despicable things. Ofcourse we haven't really been shown the real reason that Dick joined the army...maybe it was just to get away from home, but it could have been he was running away from something else.

Before the Vietnam War, military deserters were not looked upon favorably...the Korean conflict wasn't nearly as unpopular. Most of the men in Sterling Coooper's generation who are in positions of power have some military service under their belts, it's part of how they relate to eachother.