When embattled autocrats threatened by the Arab Spring’s mobilizations turned towards their armed forces for support, the stage was set for the military elite to shape the outcome of the critical junctures in 2011. Some acted as the regime’s gravediggers when they defected whereas others tried to impede change and answered the autocrats’ call for repression. Accounting for the top brass’s divergent behavior remains one of the fundamental puzzles of the Arab Spring. To do so, I argue that it is essential to problematize the relationship between the senior officers and their subordinates, rather than to treat the officer corps, let alone the military at large, as a unified actor. Just as importantly, I maintain that institutional interactions between autocratic rulers, the military elite and the mid-ranking and junior officers, shaped by decades of coup-proofing tactics, predetermined whether the military elite had a vested interest in the status-quo and, when that was the case, the capacity to defend it. In other words, I contend that institutional legacies from the post-decolonization decades need to be reexamined for a deeper understanding of opportunities and constraints structuring the top officers’ behavior in 2011. The three cases under study cover the whole range of combinations presented by the Arab Spring: a military elite that had the incentive, but not the capacity, to defend the status-quo (Egypt); a military elite that had both the incentive and the capacity to do so (Syria); and, finally, a military elite that had neither the incentive, nor the capacity, to keep the ruling elite in power (Tunisia). By analyzing these cases, I aim to present a theoretical framework applicable to other contexts as well, both inside and outside the Middle East.