My youngest brother WANTED to be career military and had an ROTC scholarship in college. However, by the time his four year obligation was up he was disenchanted by the bureaucracy of the military and the increasing attitude of political correctness (this was the early 1990s), so he got out.
A huge percentage of students at the US Service Academies are extremely intelligent young men and women from underprivileged backgrounds. They are attracted by the free tuition and guarantee of a job upon graduation. Unfortunately, many of them also leave when their obligations expire. I have worked with many West Point and Annapolis grads and they are among the most intelligent and hardest working people I've ever known, but they never intended to be career military and told me that almost none of their classmates did either.
In short, what we have is a dwindling pool to draw senior officers from. Add to this the fact that the Pentagon has quotas for women and minorities and the result is that much of the military is just like any other bloated federal bureaucracy.
The change almost certainly started with Vietnam. Things got better under Reagan, but has been going downhill ever since. The War on Terror started out on the right track, but it has becoming clear to many of us that the powers that be (under both Bush and Obama) lack the conviction to do what is necessary for a decisive victory.
It has been reported that Obama is allowing or will allow illegals to enter the military. I guaran-dam-tee you that those 3rd worlders, almost to a person from some despots little regime, will in their hearts swear their allegiance to the people giving them a job, clothing, and food. They won’t know a thing about our system and will form the Regiments of Repression with the Pink Swastikas leading them.
Fill the military with our own. In fact, inject our kids into EVERY Federal Bureaucracy, and especially Homeland Security, FBI, CIA, etc.