Strict rules govern the treatment of prisoners of war (POWs), although not everyone can agree how they should be applied.
Iraqi troops give themselves up
Commenting on the apparent capture of a number of US troops in Iraq, President Bush said he expected them to be treated "humanely, just like we'll treat any Iraqi prisoners".
Iraq's Defence Minister, Hashem Ahmad, said: "We have values and principles."
"We are committed to the Geneva Conventions. Our values, our religion and our manners make us treat prisoners of war the way they deserve to be treated."
But five Americans have been shown being interviewed on Iraqi television.
The US and British authorities have denounced this as a breach of the conventions.
The Geneva Conventions governing the treatment of war prisoners date back to 1864 and were last amended in 1949.
Some 189 countries have signed up to the tenets, which establish basic humanitarian rights for all prisoners.
THIRD GENEVA CONVENTION
Basic food rations should keep prisoners in good health
Suitable clothing should be supplied, preferably prisoners' original uniforms
Prisoners must be protected against violence or intimidation, insults and public curiosity
Prisoners should be released and repatriated without delay after ceasefire
Article 13 of the Third Geneva Convention says "prisoners of war must at all times be protected, particularly against acts of violence or intimidation and against insults and public curiosity".
The International Committee of the Red Cross has responsibility for visiting prisoners and seeing that a capturing power is obeying the rules.
Amanda Williams of the Red Cross in London said it could be argued that to expose prisoners on television could be a breach.
"It has to be said that we have also seen widespread images of Iraqi prisoners on television as well," she said.
One issue was whether the intent was to humiliate them - and also whether they would be perceived to be humiliated.
In total there are 142 articles in the third convention and Ms Williams said the "absolute priority" for the Red Cross was to be able to get access to the prisoners on both sides.
In the last Gulf War, surrendering Iraqi troops were often surprised at the humane treatment they received, says Chris Lincoln-Jones, a British commander at the time.
"At the moment of surrender they were often extremely scared because they'd heard from their officers that they would be shot by the enemy."
The emotion was such that British combatants were sometimes embarrassed by witnessing men collapse to their feet and start crying in front of them and "begging to be spared".
UK troops are well-versed in the rules for handling PoWs - everyone from an infantryman up receives an annual refresher course. There is also a separate "ethics package" which sets out the sort of behaviour that is expected of British troops in combat.
Mostly these are respected, says Mr Lincoln-Jones, who recalls an episode in the last Gulf War when an opportunistic Iraqi, shielded by his surrendering colleagues, fired a rocket-propelled grenade which killed a British soldier.
"It was a heated and tense moment and the other Iraqis might have feared for their lives. But while the culprit was killed, the other men were left unscathed."
Reports of strip searches
This time though, questions are being asked about the conduct of some troops after reports that some Iraqi soldiers are being forced to strip so they can be searched for concealed explosives.
The fear is that soldiers turning themselves over will turn out to be suicide bombers. Such an attack would have echoes of the revolt by Taleban prisoners held by American-backed forces in Mazar-e-Sharif, Afghanistan.
A full strip search would be extremely humiliating to a Muslim - it's possible to search for explosives without stripping
There was a bloodbath when prisoners, using concealed weapons, rose up against their captors.
What makes a PoW?
British command in the UK refused to comment on reports of partial or full strip searching, but the idea appalls Chris Lincoln-Jones.
"This would be extremely humiliating to a Muslim. It's possible to search prisoners without stripping them and you can pretty much tell if someone is going to try something."
When it comes to what the conventions call "humiliating and degrading treatment", the US has been in trouble before.
America has been embroiled in a war of words with human rights campaigners over its treatment of 650 alleged Taleban fighters held by the US in Guantanamo Bay, Cuba.
The US has refused to apply the Geneva rules to the captives, calling them "unlawful combatants" rather than prisoners of war.