These protections are used all the time- it just doesn't always make the news.
>demonstrably taking steps to ensure better oversight.
Like expanding the protections? We see a whistle-blower complaint right now in the news working pretty much as intended, with the whistle-blower's identity being protected.
How are SEC whistleblower protections relevant to the NSA?
As for the Pentagon, you'll note that part of what it covers is that the Pentagon Inspector General has struggled to substantiate allegations of retaliation in most cases, to the point where they ended up resorting to introduce a new system of mediation to resolve cases. Maybe that's because the allegations were bullshit, or maybe that's because the system is totally without teeth. In either case it does not illuminate the case of Snowden at all.
Yet, when the secrets being revealed are important enough, whistleblowers are met with unmasking, armed raids, and prosecution. Perhaps things really have changed in the NSA since Snowden, but given the NSA's record I doubt it.
As for the Pentagon, you'll note that part of what it covers is that the Pentagon Inspector General has struggled to substantiate allegations of retaliation in most cases, to the point where they ended up resorting to introduce a new system of mediation to resolve cases. Maybe that's because the allegations were bullshit, or maybe that's because the system is totally without teeth. In either case it does not illuminate the case of Snowden at all.