UCMJ Article 92 active-duty personnel may not:
Campaign for a partisan candidate or serve as an officer of a partisan club
Solicit votes, make monetary contributions, or engage in partisan fundraising
Speak at partisan gatherings or events
Use official equipment, uniforms, or DoD facilities for partisan political purposes
Display political signs, posters, or banners on base or in public areas, etc., etc., etc.
Civilian law: Protects public safety, prevents bad behavior, and resolves daily societal disputes. UCMJ: maintaining strict discipline, order, and mission readiness.
On the other hand, holding a sign is a no, no while being the Chairman of the Joint Chiefs of Staff it's okay to tell our enemies that he would warn them of an impending attack by the US and for troops not to follow the orders of the Commander in Chief without his approval. General Mark A. Milley anyone? Or the Col. that criticized Bidens handling of the Afghan withdrawal. ALL should be making little rock out of big rocks, no matter how much I may agree or disagree with them. Officers if you don't like what the C in C is telling you to do, resign your commission, get out and THEN open your mouth. JM-(not so)-HO!