So far, he's (season 3, episode 23):
And he's done all of these things because he has to save Earth from destruction. You can bet Jean-Luc Picard would have gotten his panties in a twist about all of these moral dilemmas, but not Archer. He knows what has to be done and doesn't let anything get in the way. Archer's the man you call when a problem's gotta be solved.
If he engages in similar acts of awesomeness after season 3, episode 23, don't tell me in the comments. I want to be surprised.