Ken Rogoff says that the dollar should be diving during this financial turmoil.

But can this extraordinary vote of confidence in the dollar last? Perhaps, but as investors step back and look at the deep wounds of America’s flagship financial sector, the public and private sector’s massive borrowing needs, and the looming uncertainty of the November presidential elections, it is hard to believe that the dollar will continue to stand its ground as the crisis continues to deepen and unfold.

Seriously, how did we go from $2/£1 at the end of July to $1.75/£1 last week?