Former Prime Minister Helen Clark says the government doesn't have any responsibility to help people like former Islamic State fighter Mark Taylor get out of Syrian jails.
The New Zealander was with IS for five years and fled in December, surrendering to Kurdish forces, because he said he was starving and reduced to begging.
Mr Taylor said he felt "stabbed in the back" by the New Zealand government, which has made it clear it cannot help him leave the prison in northern Syria and obtain a new passport.
Miss Clark told Morning Report the New Zealand government had no responsibility to get him out of jail.
"He put himself in that position. If he finds a way out, and endeavours to get a passport, I don't think there's much option to give it.
"These are not the sort of citizens any country wants but in the end they are citizens and you let the law take its course with respect to the actions they have taken while they've been with IS."
Miss Clark said a country has a duty to its citizens but the law must apply. "Those who have done the kinds of things that returning or seeking-to-return jihadis have done must expect investigation, likely prosecution, possible - in some cases probable - conviction and a jail sentence.
Miss Clark has publicly supported a return to the UK for British woman Shamima Begum who ran away, aged 15, to join Islamic State (IS). Ms Begum, now 19, is in a refugee camp in northern Syria with her newborn son. Her husband, a Dutch man who joined IS, is being held in a Kurdish detention camp.
.@BBCWorld reports Shamima Begum, London teen who ran away 2 be ISIS bride, could be prevented from returning to UK . I abhor her behaviour & “no regrets” attitude, but she left as an impressionable child & was UK born. Where else would she go? https://t.co/bFJmscmrQm— Helen Clark (@HelenClarkNZ) February 15, 2019
Afghanistan: 'the poor are the collateral damage'
Extreme poverty has risen dramatically in Afghanistan, which is in the grip of a severe drought and a Taliban insurgency, and women and children were among the worst affected, Miss Clark said.
The former prime minister recently visited the provinces of Herat and Baghdis, under the auspices of World Vision, where she said a quarter of a million people have had to walk off the land.
Many were suffering malnutrition and are living in "dire" conditions.
"I saw a five month old baby weighing at 2.8kg ... these are very, very shocking things to see.
"I really hope that the international community doesn't have fatigue with the problems of Afghanistan.
"This is a country under very severe stress with an insurgency, this year they have elections, you have a United States president indicating that he wants out of there, the United States is talking to the Taliban, the Afghans haven't been part of that conversation - there's a lot of uncertainty.
"The poor ... are the collateral damage in this, not least girls and women who face very serious challenges."
"Tens and tens of thousands" of tents around cities were housing displaced families and under these circumstances girls considered of marriageable age, some as young as 10, were under "huge pressure" to go into forced marriages, she said.
"We met two families where the mothers in the end had made a decision not to accept the bride price for a 12-year-old in one case and a 13-year-old in the other but clearly the money would have made a big difference to them.
The international community should be focusing "right now" on trying to support people to get back home.
"When all your animals have died and you've had crop failures for two seasons you have nothing." To be able to back to the land, displaced people needed money for livestock, fertiliser and seeds so they do replanting in the next rains.