Through all this, the “no-drama” Mr Obama has kept a low, indeed invisible, profile. With his innate ability to moderate highs and lows, he has been America's first “lithium president”. Fortunately, on Tuesday he stepped up to the plate on the Buy American provisions in the stimulus package, leaving little doubt as to where his sentiments, and his policy preferences, lie.

Yet, protectionism is a dangerous virus that requires a passionate response. Indeed, Mr Obama faces his two most serious protectionist challenges from the Buy American provisions that have infiltrated his stimulus package and from the China-bashing on “currency manipulation” that surfaced in the confirmation hearings of Tim Geithner, Treasury secretary .

The Buy American provisions, which would require that companies use US steel and manufacturing products in projects funded by the bill, seem reasonable. If the US has a stimulus package, why should the benefit of it extend to other countries? An influential columnist has suggested this is not what we economists call “beggar my neighbour” policy: the US is not diverting a given amount of aggregate world demand to itself at other countries' expense. Rather, it is a case of not rewarding your neighbours when you stimulate spending and are adding to world demand: neighbours should reflate their own economies. Such protectionism by the US will therefore stimulate other nations into creating their own stimulus packages.