[cookieman]

The Shire is very close to the White Towers and the Grey Havens. Cirdan and other elves might be considered a "power" of some sort. Similar, perhaps, to Lorien and Rivendell. Other Elf Lords still lived in Middle Earth, remember Glorifendel. It would would be reasonable to believe that other powerful elves, even if they aren't specifically mentioned, lived near and guarded the Shire. Also, don't forget Bombadill to the east.