[paulmd]

> If you aren't going for an actual secret (or higher) clearance

Note that despite how important it sounds, "secret" is not a very high clearance at all. It is the actual lowest classified status - there is "public trust" below that (eg for cops/etc) but that's not an actual classified standard, and FOUO/confidential/etc are not actual classification levels either, just handling guidelines.

Any time you are working on anything military-related you will probably need secret clearance at least. Anyone working with even a basic level of knowledge of military technical or operational capability, or force strength/moment/etc, will be at least Secret.

Anything that you think of as actually being deserving of "secret" most likely falls into the "top secret" category, "secret" is just the completely banal stuff, and you don't have to go far to bump into TS/SCI positions in STEM fields doing military contracting. Any sort of advanced research or development work is probably at least TS if not TS/SCI.

Actual low-level enlisted don't need to be secret (notionally you don't need to know that stuff to "go there and shoot him") but all officers are cleared secret, for example, and I would guess probably NCOs as well (so there's a cap on how high you could be in the military without it). And basically everyone in the civilian world who interacts with the military will be secret.