That is why I thought Summers argument carried more weight. Krugman and Summers were in general agreement about the problems that the US currently faces. There are many similarities between the US plight and the plight of Japan's lost decade/era. The thing that sets Summers apart from Krugman IMO is the scale of the crisis. As the above post notes, Japans house prices were down 80% (compared to the US's 30%), equities were down 80% in Japan (compared to the US 18%).
Also, while it may seem the US is caught in a policy freeze in washington, I think people forget the amount of legislation that was done a couple of years ago during the actual crisis. The politics in the US are polarized, but not to the extent that Krugman characterizes it. IMO Krugman comes off as narrow minded, and makes it seem as if the US's sole problem comes out of events in Washington (relating to one party) which I regard as over the top and inaccurate. Summers has a much more level headed response in my opinion and comes off as more common sense than Krugman.
The US was quick to act during the crisis and things like TARP where largely effective in stopping the crisis. The corporate balance sheets in the US are stronger than ever. The fed has quickly cut its rates to zero and has played a great role in preventing deflation. Our population is aging, but not to the extent as it was in japan, and people are still moving here in massive amounts, also in stark contrast to Japan's lost era. I think if you really look at, the US has similarities, but the size and scope of the problems are smaller, and our responses have been more adequate than Japans. These two things will prevent the US from ever seeing something like Japan saw.