Bear in mind that the "taper" is all about economic cover for a forced move the Fed has to make, because:
1. Deficits are shrinking and the Fed has less and less room for its buying
2. Under the surface, various non-mainstream technicalities are breaking in the markets due to the size of the Fed's position (repo markets, bond specialness, and fail-to-delivers among them).
3. Sentiment is critical; if the public starts to believe (as Kyle Bass warned) that the central bank is monetizing the government's debt (which it clearly is), then the game accelerates away from them very quickly - and we suspect they fear we are close to that tipping point
4. The rest of the world is not happy. As Canada just noted, the US monetary policy will be discussed at the G-20