People spend entire careers doing these types of analyses, so my off-the-cuff comment will always be amateurish in comparison. But here goes anyway, some exampl

People spend entire careers doing these types of analyses, so my off-the-cuff comment will always be amateurish in comparison. But here goes anyway, some examples of blunders that come from a place of arrogance, or being overeager to hit the “defect” button: - Various Roman emperors overextending and destroying what their predecessors slowly built - Indigenous peoples (especially the Americas) allying with colonial forces to defeat other indigenous enemies (won the battle, lost the war) - Brexit - Perhaps the most documented regime of all time, 1930s and 40s Germany. Specific event? The eastern offensive Edit: - Royal lineages have plenty of examples, like Louis XVI