The principle
Maintain your independence. Commit to a side or cause too early and you become a tool; remain courted by all and you preserve your value.
The application
The cynical version is to be permanently transactional. The civil version is to keep your principles fixed and your alliances flexible — let your reputation, not a banner, do your signalling.
The defensive tell — how to spot it being run on you
When someone keeps pressuring you to publicly take a side on something that does not concern your work, the pressure is the point. They want your endorsement as a chip in a different game. A polite, principled non-answer is almost always the right move.