My friend Jason Rezaian is in an Iranian prison, and I think about him every day. It's bad enough that he has been locked away for months without trial. Worse is that he has been caught up in this nightmare simply because he practiced journalism. That makes him one of many victims in an escalating global war against the press and those who work for it. The first month of 2015 suggests that this will be a bad year for free expression.

A murderous attack against the writers and cartoonists at the Paris offices of satirical weekly Charlie Hebdo was this month's most horrific episode. It reflects once more how closely freedom of expression is bound up with the essential idea of open society. In Paris not just a single institution or country came under attack but liberté — an entire approach to life.

All rights have limits, including the right to free speech. Where those limits should be drawn is a legitimate subject for public debate. Murder, however, should never be a possible outcome of that debate. Nor should state repression. Yet the Paris attack was only the most brutal in a series that set this year off to a frightening start.