A nuclear facility in Iran before and after an explosion, a village in Pakistan before and after a drone attack, a Cambodian river valley before and after a flood. The before-and-after image has become the tool of choice for analysing events. Satellite photography allows us to scrutinise the impact of war or climate change, from the safe distance of orbit. But one thing is rarely captured: the event itself. All we can read is its effect on a space, and that's where the architectural expert is required, to fill the gap with a narrative. In this groundbreaking essay, Eyal and Ines Weizman explore the history of the before-and-after image, from its origins in 19th-century Paris to today's satellite surveillance. State militaries monitor us and humanitarian organisations monitor them. But who can see in higher resolution? Who controls the size of the pixels? Interpreting these images is never straightforward.