Kiwi troops sent to Iraq need a clear objective and a way out within two years, says a military academic and former army officer who has served in the country.
Another former senior officer says any service would be best done under New Zealand's own flag, rather than with Australia in a return to the Anzac force of 100 years ago.
The Government has a team in Iraq trying to work out what New Zealand could do in the conflict against Islamic State and the Defence Force is training for a possible mission.
Retired Lieutenant Colonel Oiroa Kaihau, who lectures in defence studies at Massey University, said any deployment had to have a specific task with an end point no more than two years from the start.
"From a military perspective, we need to be clear on what we are trying to achieve and how we go about that."
Mr Kaihau most recently served in Iraq with the United Nations, spending 18 months there until October last year.
He said partnering with a friendly force from Australia, Canada, Britain or the United States would "reduce the burden".
But retired Lieutenant Colonel Bill Blaikie, who has served in intelligence and operational roles in the Australian and New Zealand armies, said the two had developed differently and would be difficult to meld into a single force.
"We operate differently. We have different cultures."
Mr Blaikie said Australia's more aggressive role in the Middle East posed a threat if New Zealand troops served with Australians.
"It does heighten security concerns," he said. "Under an Anzac banner, people won't see the difference."