 Recent military conflicts involving European nations include the 2001 War in Afghanistan, the 2003 War in Iraq, the 2011 NATO Campaign in Libya, and various other engagements in the Balkan and on the African continent.After 2014, the Russian annexation of Crimea and ongoing crisis in Ukraine prompted renewed scholarly interest into European military affairs.Due to the numerous countries that grew out of Medieval feudalism and de-centralization from the Western Roman Empire's fall, different nations have had a power struggle.