Allies agreed a new force model, which will strengthen and modernise the NATO Force Structure and will resource the Alliance’s new generation of military plans. At the Summit, Allies also committed to deploying additional robust in-place combat-ready forces on NATO’s eastern flank, to be scaled up from the existing battlegroups to brigade-size units where and when required, underpinned by credible rapidly available reinforcements, prepositioned equipment, and enhanced command and control.The Strategic Concept states that Russia is the most significant and direct threat to Allies’ security and to peace and stability in the Euro-Atlantic area. At the Madrid Summit in June 2022, NATO Leaders approved a new Strategic Concept, which describes the security environment facing the Alliance and identifies NATO’s core tasks.On 24 March 2022, at an extraordinary summit about Russia’s war on Ukraine, NATO Leaders agreed to deploy four battalions in Bulgaria, Hungary, Romania and Slovakia, in addition to the four already present in the Estonia, Latvia, Lithuania and Poland.In response, NATO has activated its defence plans, deployed elements of the NATO Response Force and significantly increased the number of forces on its eastern flank.Russia’s aggression against Ukraine poses the gravest threat to Euro-Atlantic security in decades, shattering peace in Europe and reinforcing the need for NATO to ensure that its deterrence and defence posture is credible and effective.