AFAIK, she hasn't invoked the fifth, nor asked for[1] immunity as part of a plea deal. It's just not relevant.

The principle here is that we have a legal duty to testify truthfully in response to a subpoena, and failing to do so is a crime that can be punished. There are specific carve outs, like the fifth amendment, or the various legally defined privileged communication areas (e.g. legal/medical details). But in order to avoid jail time you need to make one of these arguments before the court and win.

[1] Edit: I looked it up, and in fact Manning has already been granted immunity for this case. So the fifth is right out the window, there is no crime in which she can implicate herself by testifying.

* it's to testify against assange/wikileaks, not herself

* she was offered immunity

> How does this not fall under your 5th amendment right to not be forced to testify against yourself?

She's not testifying against herself. She's testifying against Assange.

Manning has already been tried, found guilty, and then pardoned for her crimes. She's basically immune to anything she testifies. But investigators need the evidence as they're building a case against Assange.

Manning’s sentence was commuted, not pardoned.

So interesting, I didn't know you could be forced to testify against someone else.

There are restrictions on how that amendment may be used, and ignoring a subpoena to testify against _someone else_ is not a valid use.

Besides, she hasn't pled the fifth (because she can't as it makes no sense.)

The answer to this is pretty complex and the article explains it