If US military planes sit on a Georgian tarmac or US military ships dock in Georgian harbors those locations are in fact protected under the US umbrella. If Russia were to bomb either it could start a real war. So in a practical sense the Georgian President is correct that the US is essentially going to protect those areas though said poorly. In diplo speak it was said badly and the US corrected it. Bush has already stated that he’s going to send aid ships into the Russian blockaded Georgian ports.
That’s a big deal.
Additionally, both assertions (GA and US) accomplish other objectives.