Robert Fico, the incoming Slovak prime minister, may push for partial legalization of marijuana possession.

"If smokers of marijuana, lovers of bongs [water pipes] or cakes with ingredients of this soft drug in Slovakia currently face very severe punishment, it is legitimate to raise the question of whether the threat of such punishment is effective, given the widespread use of marijuana," Mr. Fico, a lawyer whose left-of-center Smer-Social Democracy party won March 12 general elections, wrote on his blog.

Casual...