Krugman protectionist?

Tim Worstall also castigates Paul Krugman:

...you, of all people, raising the ugly spectre of protectionism? What the hell happened? You used to be very good on such points. Like back in 1996 when you wrote Ricardo’s Difficult Idea.

The link is to Krugman's defense of free trade.

Update
Awhile ago, I noted Alex Tabarrok linked to the same article. Sure, I'm senile.