President Biden authorized the Pentagon to activate up to 3,000 reservists, including 450 from the Individual Ready Reserve, to deploy to Europe. The order aims to augment existing US forces in Europe under Operation Atlantic Resolve, initiated in 2014 after Russia's annexation of Crimea. The move demonstrates continued US commitment to NATO allies and seeks to enhance deterrence along NATO's eastern flank. Biden recently attended a NATO summit in Europe, reaffirming unity against Russia's invasion of Ukraine. While Ukraine's NATO membership remains unresolved, agreements with NATO allies would reinforce its long-term security.