Many countries in sub-Saharan Africa have recently gone through agricultural transformations towards increased production of commercial crops, primarily for export, to promote national economic growth. Rural populations are often at the center of such transformations as intended targets of State policies, though their roles in strategies for rural development and poverty alleviation are contested. We approach these changes not as a simple opportunity for accumulation, but rather as an instance of ‘rupture’, through which opportunities, risks and impacts are experienced differentially by the targeted farmers. With an example from Rwanda, we ask how the State’s policy strategy and attempts to construct "ideal agricultural subjects" resonate with the actual changes experienced by farmers themselves. We present three different empirical examples to show that a) when opportunities from agricultural transformation initially arise, only the wealthiest can capture them, and even then the government is seen as the main beneficiary; b) some priority crop growers experience an increase in income and savings due to higher productivity and better prices, while those who do not grow priority crops face land scarcity and lack of employment opportunities; c) requirements to upscale livestock production do not align with the strategies or capacities of many smallholders. We show that only endowed farmers with sufficient land and ability to engage in priority crops or livestock production can take advantage of the opportunities presented by agricultural transformation, while smallholders with constraints to their adoption of promoted changes face vulnerability to dispossession and poverty. We relate these findings to our broader conceptual frame, and encourage further research to explore the integration, modification, resistance to and impacts of idealized policies in Rwanda and across sub-Saharan Africa.