Critics of the behaviour of British troops should be "slow to condemn", Defence Secretary John Reid has said.
Troops face difficult circumstances, says Reid
The circumstances they fight in are the most difficult in history because their enemy, the terrorist, is unconstrained by morality or law, he told the BBC.
Mr Reid was speaking as four possible Iraqi victims were being questioned by police about alleged abuse by British soldiers, apparently filmed on video.
He is due to make a speech on Monday in which he will defend the UK's troops.
But he told the BBC in advance an outline of what he would say in the speech at King's College, London.
"We ought to recognise the difficult situation our troops now fight in, far more difficult than any time in history because they face an enemy that is completely unconstrained.
"The international terrorist is not constrained by legality, by morality, by any conventions, Geneva or otherwise.
"Yet our troops are increasingly constrained not just by international law and conventions, the standards we want to keep, but by media scrutiny, by videophones, by mobile phones, by satellite dishes".
Terrorists advocate restricting media freedom while simultaneously exploiting television to demean hostages, he said.
"They will use our freedom as the tool to terrorise our people and we ought to be very slow to condemn our troops fighting in those circumstances".
While it was right to disapprove of abuse, it should be kept in proportion, he said, and out of nearly 100,000 British troops who have served in Iraq, there have only been five sustainable allegations of the mistreatment of civilians.
And while the media focused on the isolated security problems, it ignored the huge progress being made in building schools and hospitals, he said.
He rejected criticism of his decision to send more troops to southern Afghanistan, saying the greater danger was not to go and their mission there was clear - to defend the new government and help rebuild the economy.
Mr Reid also defended the US right to take whatever measures were necessary to combat terrorism, such as the creation of Guantanamo Bay.
British-trained Iraqi troops are strengthening security, said Reid
Shadow chancellor George Osborne disagreed, saying the detention camp should close because it damaged the reputation of the US.
On Friday, Northern Ireland Secretary Peter Hain said he would like it shut and he thought Tony Blair agreed.
In his BBC interview, Mr Reid also denied Mr Blair was going to stand down as prime minister any time soon.