I am a PhD student in a program where everyone is funded by the department by default, generally through teach, but many students are sometimes funded their advisor. The upside to being funded by your advisor is basically that you don't have to teach, and funding after 5 years isn't guaranteed anymore.
I work in STEM and many people in my field get funding from the NSA, DOD, DHS, or other military groups. I personally would not feel comfortable accepting money that comes from such sources, due to my personal ethics. I am unsure of where my advisors funding comes from, this being the issue.
How do I politely bring up this issue with my advisor? It is important to me but I have a good relationship with my advisor and I don't want to seem ungrateful or like I'm criticizing them.