Propaganda has long been a weapon of warfare, but it can be a double-edged sword. The demonisation and psychological stereotyping of enemies can come back to haunt the perpetrator.
Examples of this are to be found in a new twist in the so-called 'war on terror'. The Bush administration has advised American diplomats and counter-terrorism officials against using certain descriptions of Islamic extremists to avoid making them appear more credible.
The Americans know how to use their power in the battle for hearts and minds, although they have not always won the war. An example is the demonisation of enemy guerilla forces in the Vietnam war. Formed by Ho Chi Minh to fight for independence from France, and having also opposed Vietnam's occupation by Japan, they were called the Viet Minh, an abbreviation of a name which translates as League for the Independence of Vietnam. American officials preferred the name Viet Cong, or Vietnamese communist, but lost the battle for hearts and minds and the war.
The current administration has taken the advice of moderate American Muslims on what to call extremists. Officials are urged not to use terms like jihadist or mujahedeen, because they may boost support for radicals among Arab and Muslim audiences by giving them a veneer of religious credibility. The Department of Homeland Security says US officials may be 'unintentionally portraying terrorists ... as brave fighters, legitimate soldiers or spokesmen for ordinary Muslims'.
In similar vein, describing al-Qaeda as a movement is seen as conferring on Osama bin Laden the relevance he craves.
The words used by officials do sometimes need to be chosen carefully. President George W. Bush, for example, blundered in 2001 when he described the 'war on terror' as 'a crusade'. But this latest fine-tuning shows the battle for hearts and minds still has a long way to go. The move is driven by strategic aims. It is not motivated by a desire to limit the negative impact which the indiscriminate use of labels can have.
The guidelines will do little to help win the 'war on terror'. But if they do lead to more sensitivity in the US about the way to describe its enemies, they may yet produce a positive result.