Inside Bogotá's imposing Palace of Justice last Wednesday morning, more than 500 people were going about their business as usual. Suddenly, the quiet in the capital's BolĂvar Plaza was shattered by bursts of gunfire as some two dozen guerrillas streamed into the building from an underground garage. Armed with pistols and machine guns, the invaders quickly took over the five-story building, shooting their way to the fourth floor judicial offices, where they took more than a dozen Supreme Court judges hostage. M-19, Colombia's best-known terror group, had struck again.
When the ensuing siege was over more than 24 hours later, some...