Starfleet may have put themselves in harm's way but it was not in the protection of life but rather in the protection of secrets. Of power. Of something that would give them an edge over people who were different from them. Sadly, that included hundreds of innocent civilians.
Sometimes, they are one in the same. First...power is a fact of survival in a universe where others seek it as well. It wasn't just a matter of dealing with people who are different from them. The UFP has real enemies. There is nothing made up about that.
Now, did they approach it wrong? Making the move into the Taurus reach under the guise of colonization? Perhaps. That is a legitimate debate.
But the original goal of that expedition, to try to explore and uncover the secrets of the Taurus Reach, for all the reasons, INCLUDING the pursuit of power, aren't illegitimate ones for a state entity to take.
Nogura on the other hand simply tried to deal with the cards he was dealt and didn't let the consequences change his mind. He seems to be the sort that feels you cannot make an omelette without breaking a few eggs. The crew of the Omari Ekon and the scientists of the Vault just happened to be the eggs in the carton he had. He saw the consequences and he moved on, unmoved. As opposed to Reyes I feel that Nogura would do everything exactly the same way that he did. Right or wrong, he stands by his decisions.
In a modern setting, Nogura was G.W. Bush or Dick Cheney and Reyes was Colin Powell, although Powell waited until he was out of power to admit he was wrong.
I disagree. I think Nogura was a McCrystal or Patraeus. He didn't make the policy, nor did he necessarily approve of it's architecture. But he was assigned command and he was going to do his best with it.
It wasn't his policy. As he himself thought about himself at one point in this book, he is a soldier. A commander.
They don't make the policies. They execute them. And unless they are given an order clearly unlawful, they are duty bound to execute to the best of their ability.