San Fancisco ? The lawyer and parents of American-born Taliban soldier John Walker Lindh asked President Bush on Wednesday to commute his 20-year prison term, citing the case of an Australian man who was sentenced to less than a year for aiding terrorism.

Lindh, 26, was captured in Afghanistan in November 2001 by American forces sent to topple the Taliban after the Sept. 11 terrorist attacks. He was charged with conspiring to kill Americans and support terrorists but pleaded guilty to lesser offenses, including carrying weapons against U.S. forces.

Lindh’s lawyer and father said the lighter sentence given to Australian David Hicks should be reflected in Lindh’s case.

Lindh converted to Islam and went to Afghanistan to fight for the Taliban against the Northern Alliance, which received U.S. backing. After his capture, he was imprisoned near Mazar-i-Sharif and was caught up in a riot that led to the death of CIA agent Johnny Spann, but there was no evidence linking him to Spann’s death.