US ships in Black Sea?

As far as I can judge Russians are well prepared for the Olympics and they don't need help of US Navy forces there, but it looks to me Americans want to use the Olympics as cover and get closer to Ukraine since they declared about their full and absolute support of protesters. And this is very strange because the majority of protesters consist of Ukrainian nationalists who already declared their intensions to clean Ukraine from Jews and other enemies. I do not understand why democratic America supports some Nazis and advance battle ships there with 600 of marines. By all appearances that do not look like rescue or evacuation operation because Ukrainian nationalists have no control over eastern and southern parts of the country and Americans will be right there so I think they will provide nationalists with military aid to gain control over these regions. However good America's intensions might have seemed, their true goal is capturing Ukraine, not Olympics.