US very clearly sees China as its mains competitor, and it will be all too happy to leave Europe holding the bag with the Ukraine debacle. The fact that Nuland just got dismissed and replaced with a China hawk is a pretty clear sign of things to come. Europe is entirely dependent on US both militarily and economically now, and if US quit NATO then Europe would still be just as dependent on US as before. Military industry will keep selling weapons to Europe, but there won't be any more obligations on the part of US allowing the neocons to focus on trying to provoke a war with China.