The Conventional Arms Control system in Europe is characterised by three complementary agreements, negotiated, and implemented during the Cold War: The Conventional Armed Forces in Europe (CFE) treaty, the Vienna Document, and the Open Skies Treaty (OST). These three instruments were designed to reduce the risk of war and CFE in 2007 and de facto withdrew in 2015; the CFE adapted version was never ratified by all participating states. The Vienna Document seems no longer adequate to address current security challenges and modernisation attempts have constantly failed. Lastly, the Trump administration formally withdrew from the OST in November 2020 and Russia provide a higher level of predictability and confidence in European security through cooperation and exchange of military information.