The Defence Force was known internationally as one that upholds the rule of law, which was why its soldiers were liked as trainers in Iraq, he said.
"It's a huge reputational issue. There is a legal terminology for that that you can go into but there'd better be hard evidence to back that.
"If somebody makes an allegation today about Task Group Taji, because we train on our reputation, we will throw all the resources we can at that to ensure the facts around the case and if there is none, we will continue with our strong reputation we have had as a modern Defence Force."
Defence Minister Gerry Browlee said it was difficult to comment without reading the book, though he had been given an outline of the allegations.
He echoed comments by the NZDF that the operation had been widely investigated and that no civilian casualties had been found.
"Our position hasn't changed since 2011. I can't see why it would be changing.
"What I've been told is that he is talking about an incident that has been extensively investigated, based on previous accusations of civilian deaths.
"And those accusations have not been proved at all accurate. Quite the opposite.
"There have been several investigations including by ISAF [International Security Assistance Force] itself and the allegations that are made simply have not been substantiated in any way whatsoever."
Brownlee also criticised Hager for the timing of his book's release.
"Mr Hager has written a book with the idea of selling it. It's election year. It shouldn't surprise anyone that he has brought out a book that is designed to cause a degree of trouble.
"But this time, I've got to say, he has totally missed the mark again."
Asked what would convince him to reopen the investigation, Brownlee said: "I think when you've had three inquiries of the nature that have taken place, it's hard to think there would be anything that would make you want to re-open an inquiry."
The allegations in Hager and Stephenson's book would probably not be enough to launch an inquiry, he said.
"But as I've said to you I haven't had the chance to read his book but I haven't been briefed that there is anything new in what he is saying.
Revenge raid
Hager and Stephenson's
book alleges
that six civilians were killed and another 15 people were injured in an SAS "revenge raid" to pay back Taliban insurgents for New Zealand's first fatality in Afghanistan.
The allegations were in direct contrast to assurances given by former Prime Minister John Key, former defence ministers Jonathan Coleman and Wayne Mapp and the New Zealand Defence Force.
The official story was that nine insurgents were killed during the raid. The book alleges no genuine targets were found and women and children were among those killed in a bombardment from attack helicopters.
The book, Hit & Run: The New Zealand SAS in Afghanistan and the meaning of honour, quoted one military source as saying: "They knew they had committed an atrocity."
Another was quoted saying, "it was definitely a revenge raid".
The book claimed Mapp later told the friend the raid was ""our biggest and most disastrous operation". The book stated that he called the raid "a fiasco".
Hager and Stephenson have written extensively on New Zealand's involvement in Afghanistan.
The book stated the allegations were based on information from more than 30 people, and many of the approximately 20 New Zealand and Afghan military sources were directly involved in the raid.
- Additional reporting Audrey Young
