Speaking of the fall of the Roman Empire or any nation, Teddy Roosevelt said...
"The laws were the same as they had been
..but the people behind the laws had changed, and so the laws counted for nothing."
Marcus Tullius Cicero Roman Statesman Speech in the Roman Senate - 42 BC:
A nation can survive its fools, and even the ambitious. But it cannot survive treason from within. An enemy at the gates is less formidable, for he is known and carries his banner openly. But the traitor moves amongst those within the gate freely, his sly whispers rustling through all the alleys, heard in the very halls of government itself. For the traitor appears not a traitor; he speaks in accents familiar to his victims. He rots the soul of a nation, he works secretly and unknown in the night to undermine the pillars of the city, he infects the body politic so that it can no longer resist.