In the aftermath of Friday's massacre in Houla -- including at least 34 women and 49 children – Washington is divided over how to accomplish regime change in Syria. Mitt Romney says the US should arm Syrian rebels. President Obama is focused on diplomacy. There's also dispute within both parties of Congress. Who are the rebels? What would it take for them to defeat Assad's army? Would arming them lead to chaos or a proxy war between other countries? How long can the world stand by while a government slaughters its own people?