Disinformation shapes perceptions, misleads public opinion, and distorts political discourse. Fake news and manipulative content about migrants and refugees are particularly pervasive. Following Russia's invasion of Ukraine, disinformation on Ukrainian refugees is increasingly being used to sow uncertainty and division within Europe. This can become not only a danger to the people seeking protection, but also to the cohesion of society and democratic institutions itself. So far, existing counter-disinformation strategies mostly follow a 'debunking approach' focussing on fact-checking. However, so far this is not enough to prevent disinformation from shaping the political debate. This publication therefore argues for a pre-emptive 'prebunking' strategy centred on monitoring, foresight and societal resilience to fight not only disinformation but also its spreading.