In response to the 2014 Russian annexation of Crimea, the Obama administration established the European Deterrence Initiative (EDI), a program dedicated to bolstering American military presence in Central and Eastern Europe. The EDI has funded Operation Atlantic Resolve, a collective defense effort to enhance NATO's military planning and defense capabilities by maintaining a persistent rotation of American military air, ground and naval presence in the region to deter perceived Russian aggression along NATO's eastern flank.[137][138] The Enhanced Forward Presence (EFP) force was established by NATO.