It didn't last because it couldn't. The bid for risk catalyzed by the Bank of England's emergency intervention in the UK bond market fizzled Thursday, as US yields resumed their upward march and the curve bear flattened. It was just as well. Wednesday's rally was counterproductive for a Fed bent on engineering tighter financial conditions. In all likelihood, US policymakers were displeased with the sugar high from the BoE's pension rescue operation. The S&P gave back all of the prior day'