Defecting Libyan diplomats are among those saying there's a "massacre" taking place in their country and demanding that Colonel Moammar Gadhafi step down after 41 years in power. Estimates of the numbers dead in Libya are reaching into the hundreds: protesters killed by soldiers and by mercenaries from other countries. In a defiant speech, Gaddafi said he would fight "to the last drop of blood," despite defections by diplomats and military desertions. Some tribal leaders have threatened to stop the flow of oil from one of the world's major sources unless security forces "stop the bloodshed." We hear more about the most violent Middle Eastern uprising so far and the implications for the US, Europe and the rest of the Arab world.