PARIS — In democracies, justice is supposed to be independent. Some prosecutors and investigating magistrates, however, conveniently forget this. Indeed many among them are deeply enmeshed in politics, pursuing agendas — and vendettas — of their own.

The phenomenon of politicized prosecutors and investigating magistrates is becoming global, arising in democracies as diverse as Japan, Italy, France, Spain, Turkey and Argentina. In all these countries, prosecutors and magistrates hurl accusations of corruption against governments and ruling parties — charges that also happen to suit the political and institutional interests of the magistrates.

Japan's state prosecutors have, for example, carried out investigation over falsification of political funds reports of DPJ General Secretary Ichiro Ozawa. That three close aides to Ozawa have been indicted — although Ozawa himself has not — only months after the Democratic Party of Japan's victory strikes many Japanese as odd, given the well known corruption of the LDP when in power.