Monica Bernardi, Carlos Manzano, Adriano Cancellieri, Simone Tosi
This article argues that socio-ecological transition in Italian cities unfolds less as a coherent policy trajectory and more as a fragmented and contested field of governance devices, discourses, and coalitions. Drawing on a systematic mapping of sustainability-related policy instruments adopted in Milan between 2015 and 2025, discourse analysis, and key-informant interviews, Milan is approached as a critical urban laboratory. The paper shows how sustainability is produced through a proliferation of partially autonomous policy instruments, what we conceptualise as sustainability molecules, whose alignment is periodically attempted around major turning points such as mega-events, crises, and political cycles. These moments typically do not produce systemic integration; instead, they tend to reconfigure urban coalitions and legitimise selective interpretations of sustainability, highlighting its dual role as both a transformative agenda and a dispositif of urban legitimation.