Germany will on her side never break the peace. Germany wishes to be on an honourable footing with the neighbour peoples. - Adolf Hitler

The only preventative measure one can take is to live irregularly.

You know my opinion of Franco... We ought to keep these Red Spaniards on the back burner... They're lost to democracy, and to that reactionary crew round Franco too... I believe you to the letter, Speer, that they were impressive people. I must say, in general, that during the civil war the idealism was not on Franco's side; it was to be found among the Reds ... one of these days we'll be able to make use of them... The whole thing will start all over again. But with us on the opposite side.

By looking after his relatives' interests as he did, Napoleon furthermore displayed incredible weakness on the purely human level. When a man occupies such a position, he should eliminate all his family feeling. Napoleon, on the contrary, placed his brothers and sisters in posts of command, and retained them in these posts even after they'd given proofs of their incapability. All that was necessary was to throw out all these patently incompetent relatives. Instead of that, he wore himself out with sending his brothers and sisters, regularly every month, letters containing reprimands and warnings, urging them to do this and not to do that, thinking he could remedy their incompetence by promising them money, or by threatening not to give them any more. Such illogical behaviour can be explained only by the feeling Corsicans have for their families, a feeling in which they resemble the Scots. By thus giving expression to his family feeling, Napoleon introduced a disruptive principle into his life. Nepotism, in fact, is the most formidable protection imaginable : the protection of the ego. But wherever it has appeared in the life of a State — the monarchies are the best proof — it has resulted in weakening and decay. Reason : it puts an end to the principle of effort.
In this respect, Frederick the Great showed himself superior to Napoleon — Frederick who, at the most difficult moments of his life, and when he had to take the hardest decisions, never forgot that things are called upon to endure. In similar cases, Napoleon capitulated. It's therefore obvious that, to bring his life's work to a successful conclusion, Frederick the Great could always rely on sturdier collaborators than Napoleon could. When Napoleon set the interests of his family clique above all, Frederick the Great looked around him for men, and, at need, trained them himself.
Despite all Napoleon's genius, Frederick the Great was the most outstanding man of the eighteenth century. When seeking to find a