During a vigorous panel debate on US global relations at the World Economic Forum in Davos, Switzerland, several European officials attacked President George W. Bush's Iraq policy, but Mr Howard stood up to defend his ally.
"Some of the criticism (of the US) by some of the Europeans is unfair and irrational," Mr Howard said in the panel debate, organised by Britain's BBC TV.
"I mean the negative mindset of the last five minutes (of this debate) is ridiculous - of course America has made mistakes," he said.
Later Mr Howard told The Australian he found the European "irrational level of anti-Americanism" perplexing.
"It is a sign of parochialism and it is disturbingly intense."
He said the BBC debate "was based on an anti-American mindset which was established right at the beginning by the moderators from the BBC".