That thousands of atrocities were committed is well known. But most are little documented, and have been allowed to recede out of the public memory. This was due mostly to the minute importance placed on them by the Soviet authorities, who wanted to confuse their wartime massacres with those of the Nazis, to lose the truth in the chaos of war.
So it's unfair for the West, which has on various occasions demanded that trials of war crime suspects be speeded up, to expect that the blurry mess of the 20th century can be placed in sudden focus, and for these crimes to quickly be solved.
Yet time is running out for cases like the one on alleged former Soviet officials on the Estonian island of Saaremaa, which is continuing this week. Victims, witnesses and the guilty in both Nazi and Soviet crimes are all dying of old age.
It's essential, for all generations, that as much about the truth in these terrible crimes be raked over and brought to light as possible, as soon as possible.
Both the evidence and the desire to find that evidence may disappear.
It's obvious that future generations need to know about the horrors of the past, so the horrors don't happen again in the future.
But so far in the Baltic countries, the trials of Nazi officials have by far outnumbered those of Soviet officials. To many in the West, this says unfortunate things about nationalities denying responsibility for complicity in the atrocities that accompanied the invasions and occupations like a plague.
And what does that say to the younger generation? That one form of atrocity is better than another?
The worst crime now may be complacency. After half a century of being suppressed, Estonians, Latvians and Lithuanians are out on the town, enjoying themselves. They have a lot to catch up on. But it would be a mistake to fail to see the significance of bringing the criminals of the past to justice, no matter how old or frail they are. Because justice, finally, must be done.