PHUKET, Thailand (Reuters) - North Korea has no friends left to shield it from the international community's demands that the country scrap its nuclear activities, U.S. Secretary of State Hillary Clinton said on Thursday.Clinton said many nations had told a low-level North Korean delegation at a regional security meeting on the Thai island of Phuket to give up its nuclear weapons. Speaking at a news conference, Clinton said North Korea's pursuit of its nuclear ambitions could provoke an arms rac