Washington: More than 20 years after Chinese troops crushed pro-democracy protests, a top Tiananmen Square student leader says the bloodshed was unavoidable as the communist leadership was set on using force.

In a new book, Chai Ling, the students' commander-in-chief who later escaped China in a cargo box, recounts years of anguish as she wrestled with memories of Tiananmen and describes how more recently she found a calling in faith.

Chai, who is now 45 and lives in Boston with her American husband and three daughters, voices outrage at Tiananmen accounts that charge that she could have ordered students out more quickly or that she sought a violent showdown.

"The bottom line for me about Tiananmen Square is that the student leaders never expected, hoped for or anticipated the Chinese government would actually open fire on its own citizens," she writes in "A Heart for Freedom," which will be released in October in English and Chinese.

Chai dismisses suggestions that an earlier exit from Tiananmen Square would have saved lives, believing that hardliners in the communist leadership would have found another pretext to rein in expanding protests.

"The government was determined to retake control of the city and send a message of fear and intimidation to the people -- to 'kill the chicken to shock the monkey,' as the Chinese saying goes," she writes.

Chai says she believes the leadership decided to use force as far back as April 25, 1989, when supremo Deng Xiaoping accused students of seeking to topple the Communist Party. A state media editorial the next day warned that the leadership would end the "turmoil."