Luckly, the military is self correcting. If you can be counted on and trusted, your squad mates will look after you as you look after them. You chance of survival just got better. If you cannot be counted on or trusted, no one will look after you, and your chances of survival just got much worse. And this happens regardless of race, creed, gender, or sexual orientation, at least in my opinion.
I think this is a great point, and as GunnyG posted above, Loyalty runs up and down the chain of command. When it doesn't you end up with disasterous consequences. But, the key word in your statement above is trust. Trusted to do or not do what? Trusted to say or not say what? In the Marine Corps I was in Trust was founded upon the Constitution of the United States, the USMC Field Manual and inside that the Marine Corps Leadership Traits and Leadership Principles.
Please show me where DADT fits into these principles. The Sergeant Major is undoubtedly a great Marine, but were I to be writing his fitness report I'd be focusing on these four:
◦The quality of faithfulness to country, the Corps, the unit, to one's seniors, subordinates and peers.
◦Avoidance of providing for one's own comfort and personal advancement at the expense of others.
◦Uprightness of character and soundness of moral principles; includes the qualities of truthfulness and honesty.
◦The mental quality that recognizes fear of danger or criticism, but enables a man to proceed in the face of it with calmness and firmness.
I'm not trying to presume, but DADT was successfully fought by the three previous commandants and has now been rammed down our throats. What could the senior Marine leadership - both enlisted and officer done to prevent this?
John Kerry found this out the hard way - luckily for us.