back in the day before political correctness took over, it was almost standard Soviet practice to try and blackmail key enemy (US) figures by extra marital affairs. Get the General in bed, record the compromising material, then give him a choice...give us what we want, or we tell your wife. A few succumbed to the blackmail....
Even if there was no affair involved, but simply some embarrassing detail in an officers persoanal life, that could be exposed, Soviet espionage would atteempt to use that.
In the Australian military, above a certain security clearance, officers had to make full disclosures about their sexual preference, finacial situation, girlfriends and even friends. It was really quite onerous. A failure to disclose was an indictable offence.
Herein lies the problem for the US at the moment. We cant be sure that national security has not been compromised because these affairs were not disclosed. that makes the officers vulnerable. Without realizing it they become a security risk.
However, i do believe this is not the main issue. I strongkly suspect political motivation here....it just doesnt sit right the way its playing out.