To paraphrase an old saying, hell hath no fury like a father who believes his son has been wronged.

On Thursday, Frank Lindh, father of John Walker Lindh — the so-called “American Taliban” imprisoned in 2002 for aiding the enemy in Afghanistan — told a rapt audience at San Francisco’s Commonwealth Club that his son is neither a traitor nor a terrorist, but rather “a decent and honorable young man embarked on a spiritual quest.”