The author of a new book on the break-up of the ANZUS alliance says New Zealand sent troops to Afghanistan to help re-establish its security relationship with the United States.
Labour Party foreign affairs spokesperson Phil Goff disagrees with Gerald Hensley's assertion and says the Government at the time was not trying to curry favour with the Americans.
Mr Hensley was the head of the Department of Prime Minister and Cabinet during the time frantic diplomatic efforts failed to save ANZUS.
His book Friendly Fire charts the collapse of the alliance between New Zealand, the US and Australia after the then Labour Government introduced its nuclear-free policy in 1984.
Mr Hensley says this country has been trying to win back favour with the US ever since the alliance collapsed, but sending troops a decade ago to Afghanistan wasn't in the country's national interests.
Mr Goff says al-Qaeda represented a threat to New Zealanders and the citizens of other countries and New Zealand was right to go to Afghanistan - just as it was right to stay out of the invasion of Iraq.