Defense.gov News Article: U.S. Sends More Marines to Romania, Navy Vessel to Black Sea http://www.defense.gov/news/newsarticle.aspx?id=121959
With the crisis in Ukraine, it is understandable that the US would want additional assets in case of an emergency.
Incidentally, the Special Purpose Marine Air-Ground Task Force Crisis Response (SP-MAGTF CR) was set up specifically to deal with this kind of scenario, after the death of the US ambassador to Libya, Christopher Stevens.
