Europe because that where there two allies united kingdom and France are. Europe is also important to the U.S. because of its geographical proximity
to some of the world’s most dangerous and contested regions.The basing of U.S. forces in Europe generates benefits outside of
Europe. Recent instability in North Africa, most notably ISIS operations
in Libya, has shown the utility of basing robust U.S. military
capabilities near potential global hot spots. For example, when ordered
to intervene in Libya against Muammar Qadhafi, U.S. commanders in Europe
were able to act effectively and promptly because of the
well-established and mature U.S. military footprint in southern Europe.