is the U.S. Like Greece?

Paul Krugman says no, and has a graph:

And he spanks David Leonhardt:

Are We Greece?: David Leonhardt tries to draw parallels. But how strong is the parallel, really? I would really question this comparison:

The numbers on our federal debt are becoming frighteningly familiar. The debt is projected to equal 140 percent of gross domestic product within two decades. Add in the budget troubles of state governments, and the true shortfall grows even larger. Greece’s debt, by...