Before 1950, the United States intervened in large scale counterinsurgencies twice as often and intervened almost exactly as long as interventions after 1950. Yet, U.S. supported states developed before 1950 tended to survive an average thirty years after U.S. withdrawal. In contrast, U.S. supported states after 1950 have tended to survive only three years. The central question of this examination is why did U.S. military counterinsurgency (COIN) interventions before 1950 produce host-nation governments and host nation security forces that tended to endure ten times longer than interventions after 1950? My central argument is that when the U.S. military deeply embeds within and inhabits host-nation institutions (institution inhabiting strategies) then, state longevity improves in the course of counterinsurgency (COIN) interventions. Inversely, when the U.S. military employs strategies of lower embeddedness (institution influencing strategies) then, state longevity decreases in the course of counterinsurgency (COIN) interventions. I compare cases of intervention in tabula rasa or erased governance in the Philippines 1898-1913 and Iraq 2003-2010. The former employed high degrees of embeddedness in both governance and security development and the latter low degrees in both. I also compare cases of intervention in existing governance in Nicaragua 1912-1933 and Vietnam 1964-1972. The former employed a high degree of embeddedness in host-nation security force development and a low degree in host-nation government development while and the latter employed low degrees in both. My research finds a correlation between degree of embeddedness in developing security and governance and state longevity after withdrawal of U.S. forces. The implications for this study are salient today. Where state fragility has progressed to the point where intervention by conventional military force is required to arrest it, institution influencing strategies like Advise and Assist are insufficient. And while trusteeship forms of relation have been largely dismissed since decolonization, the apparent efficaciousness of neo-trusteeships and shared sovereignty relationships in places like Kosovo, East Timor, and Sierra Leone hold out the promise of more effectual strategies for state building in counterinsurgency interventions. / PHD