stated the days when the debt-ridden uncle sam could leisurely squander unlimited overseas borrowing apeersd. china's own credit rating agency dagong is equally pessimistic, downgrading its u.s. credit rating twice in less than a year. from a-plus down to "a." as america's economic ideals don't fundamentally change, it will not increase its ability to repay its debt, and the situation will only get worse, the agency's chairman says. but few in china expect their government to stop funding american debt through the purchase of u.s. treasuries. china is america's largest creditor. but it's also counting on americans to continue buying its products. celia hatton, cbs news, beijing. >>> this morning on "the early show," more on the global stock sell-off. i'm randall pinkston. this is the "cbs morning news." this portion of the c"cbs mornig news" sponsored by shift move free advanced. nced. ,,,,,, >>> here's another look at this morning's top stories. stocks are sinking this morning on markets around the world, following the worst day on wall street in 2 1/2 years. for a third straight night, ri