It seems almost inevitable that as the perceived economic benefits of free trade collapse, more countries have started slapping up protectionisht measures, such as tariffs. As WaPo's piece notes, increased tariff activity (such as the United States's Smoot-Hawley tariffs) are widely blamed for exacerbating the Great Depression... and so... here we go again.
In some sense, we have no one to blame but ourselves for not pushing harder to get the "Doha Round" of international free trade talks through, largely by not making it worthwhile enough for developing countries (and because of our, and Europe's, insistence on coddling our already over-coddled agricultural sectors... cough, cough... Iowa.)
Anyway, here we go again. At the moment, it is developing countries such as Indonesia, Brazil and Russia that are slapping on tariffs; if, in fact, the titans of world trade (that would be the EU, the USA, Japan and China) join the protectionist party... economic activity will slump some more...
The good news is that if there is a world figure in a position to call for world cooperation, that figure is Barack Obama. Just one more thing to add to his ever-growing list of priorities. (Barack, surely we just wanted you to know, we're counting on you. And don't call me Shirley.)