I've read some very interesting papers on why collusive cliques based around concealing a shared crime or proclivity tend to out-compete others.

Game theory suggests these have much greater internal cohesion and trust in one another, due to the kompromat they implicitly hold over one another. Cliques without mutual blackmail have weaker ties.

There may well be something in it - it certainly correctly predicted the decline of "Lavender Mafia" cliques within the Catholic Church with increasing community tolerance for homosexuality.

And Waffen-SS units with a shared history of sickening crimes often fought harder and longer than Wehrmacht units without this.

But otherwise it is difficult to find evidence of something secret by definition.

I do believe Netanyahu's public statements about there no longer being war crimes is an effort to create the world's largest and least-elite mutual-blackmail clique. It shows a certain desperation. 

 Supposing the Israeli PM is a bad guy, which I don't know and don't hope, that doesn't mean all Israel is evil, it seems obvious but we should specify these, because of that, innocent Jewish will be attacked, but of course it's the same for anyone, blaming someone should really be done carefully, especially today, if we don't want innocent people to be attacked because of words dropped too quickly on Internet. 

 Systems, incentive structures, and institutions can foster evil by design, whatever the original morals of the members they recruit.

The televised behaviour of the contemporary IDF is probably the strongest proof of this we are likely to see.