The daughter of Poland's last communist leader, Gen. Wojciech Jaruzelski, says her father's innate pessimism and fear dictated his decision to impose martial law against the Solidarity freedom movement in 1981.

Jaruzelski, 89, has said that he chose a "lesser evil" in imposing martial law on Dec. 13, 1981, in the hey-day of Solidarity, which opposed communist rule. He maintains a Soviet military intervention and bloodbath was the other option.

Thousands of dissidents were arrested and some 100 people were killed during the 18 months of the clampdown.

In a new biography of her father, Monika Jaruzelska says "that pessimism and a sense of fear determined many decisions ... including that most important one."

Poor health prevents Jaruzelski from standing trial over his decision.