After the G20 failed to reach any consensus on currency issues and trade imbalances, President Obama took a direct shot at China Friday, saying the renminbi "is undervalued...and China spends enormous amounts of money intervening in the market to keep it undervalued." The President's comments cap (at least for now) a period of extraordinary public debate among politicians and policymakers -- past and present -- over currencies and the Fed's QE2 program. Ahead of the G20 confab, Germany's finance minister, Wolfgang Schauble called U.S. policy "clueless," while foreign ministers from China, South Africa and France (among others) questioned the wisdom of QE2. Adding insult to irony, former Fed Chairman Alan Greenspan piled on in The FT, where he warned the U.S. is "pursuing a policy of currency weakening." That in turn, prompted a sharp rebuke from Treasury Secretary Tim Geithner, who told CNBC: "We will never seek to weaken our currency as a tool to gain competitive advantage or to grow the economy." Michael Pento, senior economist at Euro Pacific Capital, says the U.S. doesn't have a leg to stand on when it comes to discussions about currencies, calling Alan Greenspan's comments the "height of irony and hypocrisy," given his easy money policies at the Fed. "The U.S. is the number one currency manipulator on the planet," he says. "We print up a lot of dollars [and] we can consume more than we produce because of that." But that policy makes for a "chronically weak" dollar and puts America at the mercy of its foreign creditors, Pento says, restating a warning about the risks of a true dollar crash and sky-rocketing interest rates if we don't change course, soon. It won't happen overnight, but China is plotting its own exit strategy by slowing rolling its Treasury holdings into the short end of the curve, he says, suggesting other foreign investors will follow suit. "The credibility of this country is falling faster than the dollar," Pento says. "One day you'll have a Treasury auction without indirect bidders and only Ben Bernanke" will want to buy U.S. debt, he says. To avoid such a "watershed event," Pento recommends we adopt the bulk of the Deficit Commission Panel's recommendations, as detailed here. He also wants a return to the gold standard, a controversial idea World Bank President Robert Zoellick broached this week. Going back to the gold standard "would be painful" and even lead to a depression in the near term, Pento concedes. But "all the imbalances would be reconciled and we can start over again with a real economy http://finance.yahoo.com/tech-ticke...ency-manipulation-pento-says-yftt_535604.html