Here is today's Washington Post story on the GAO's press release. The press release itself and GAO's summary of the issue are here and here.
This quote from the GAO summary is the heart of the matter:
Gaps in research data, foreign language capability, staffing, and resources hinder the United States’ ability to best target and communicate with key foreign audiences.
In other words, more money and personnel are needed. As the WaPo story points out, the budget for public diplomacy efforts, which was $358 million for 2008, is a mere pittance to a government that allows its Defense Department to contract out over $100 million for strategic communications services next year in Iraq alone.