Torture is the act of causing physical or mental anguish, pain and/or harm, sometimes in order to achieve a specific result, such as obtaining information ("enhanced interrogation" for the politically correct), or sometimes as revenge or to satisfy the sadistic nature of the torturer.
In spite of a long history of use by governments, religions and individuals, research has shown that information obtained by torture is notoriously unreliable. In fact, torture is unreliable for three reasons:
- Under torture a person may say whatever the torturer wants to hear. He may incriminate innocent people or confess to crimes he knows nothing about.
- A person under torture has no real interest in helping the torturer - he is not a willing ally. Assuming that he has not been coerced into simply saying whatever his interrogator wants to hear then his information is likely to be ambiguous, dangerous or simply wrong.
- Tortured people aren't exactly in the best state of mind to give correct information, even if they wanted to in the first place.
In addition to those three problems of not getting accurate information, torture hurts your overall policy effectiveness in several ways. This is more applicable for governments than for, say, bank robbers but all the same:
- Torture makes allies and neutral parties less friendly towards you; if you torture your foes but your opponent does not, what's your moral justification for them working with you? This effect cannot be understated; in the American Civil War the Emancipation Proclamation was a huge boon for the Union not just for the liberated slaves but also because it made France and Great Britain withdraw a considerable amount of support from the Confederacy due to the clear moral contrast between the two sides.
- Torture makes other avenues of negotiation/information gathering ineffective. Even if contacts are otherwise inclined to help the information-seekers the possibility of being tortured as well for information makes them clam up and feign ignorance; after all any organization brutal enough to torture people for information can't exactly be trusted to keep promises or play fairly. If Gestapo agents were offering 100,000 marks for primo information on the underground Communist party, what makes you think that they wouldn't just torture you for the information when you come forward to collect the reward?
- If torture comes to light, it can be used by your adversary as proof of how brutal and inhumane you are, which will increase popular support and make whatever cause the victim fought for stronger. If someone thinks they will be tortured, they will fight harder and be less likely to surrender or co-operate.
- Government-sanctioned torture creates a breeding ground for further atrocities. As dodgy as capital punishment is, most countries go out of their way to make the process as transparent as possible. However, to avoid the previous problem most torture is done (even in the most brutal of regimes) with a heavy dose of secrecy. This cocktail of opaqueness and necessarily dehumanized torture candidates inevitable leads to further human rights scandals.
- Torture also creates the problem of needing to do something with the captive once they do give up the information. Even if you otherwise have no interest in whether they live or die, you can't exactly let them go because they're a witness to what happened and will probably oppose you. You could just imprison them indefinitely, give them a (probably show) trial, and/or execute them -- at the cost of hurting your international standing even further.
Although outlawed by most countries, torture is still practiced by some, particularly dictatorships and other tyrannical or authoritarian governments. The United States has a prohibition against it, but recently circumvented this by outsourcing its torture to private contractors, ensuring that no-one was actually tortured on U.S. soil, and, as a last resort, redefining the Geneva Conventions to suit. Ain't obeying the law grand?
An example of the unreliability of torture can, surprisingly, be gleaned from the Larry Craig affair. Apparently just the thought of the damage to his reputation and position in society made him plead guilty to a sex-related disorderly conduct charge, even though he now claims he was not guilty. Imagine what he would wrongly plead guilty to if torture, rather than shame, were in the offing? And this man was a tough conservative, not a librul weakling.
The military (and, formerly, the CIA) claimed that torture is a worthless tactic, as the victim will admit anything to stop the torture. For gathering useful intelligence, gaining trust, bribery or undercover operations are far more useful tactics, and don't result in the physical or mental destruction of anyone.
With regard to terrorism, also, torture can also serve as a catalyst to increase terrorist activity. A terrorist organization needs to play to prejudices or other malcontent on the part of its potential recruits; beating, arresting and especially torturing or killing people gives terrorists this sort of rallying call. Treating them like human beings and entering into legitimate, fair political negotiation does not.
An example of this can be seen in the IRA. The British fought them militarily for nearly a century, with varying levels of success, but were never able to actually defeat or disband the organization until they switched tack, beginning serious negotiations not for a cease-fire, but for a somewhat legitimate autonomous Northern Ireland and an end to discrimination against the Catholic population, which would remove the motivation for many Irish Catholics to join the IRA. Although some stragglers and fanatics remained, the IRA mostly disbanded.
It has been admitted the US military engaged in torture, including waterboarding, at the US Navy base in Guantanamo Bay, Cuba. (In fact, many of the methods later used at Abu Ghraib apparently came from Guantanamo.) The detention facility (Camp Delta, formerly Camp X-Ray) is an interesting study into the follies of America's current policies regarding detainees. Despite the inhumane treatment of detainees, clear violations of the Geneva Convention (And the Vienna Convention on Treaties, which allows the camp to exist in the first place) Camp Delta and X-Ray have gathered little workable intelligence. While some high ranking al-Qa'ida members have been captured or killed, the organization (Which is, in reality, more a philosophy than an actual organization) still remains active worldwide. The insurgency in Afghanistan is as strong as ever, and al-Qa'ida retains significant infulence throughout the Middle East and Africa. Camp Delta is still operational to this day, despite Barack Obama's promise to close it. Karl Rove, also known as "Bush's brain", said he "was proud we used techniques that broke the will of these terrorists". 
- See main article Extraordinary rendition.
Extraordinary rendition is when the United States, determined to break someone without dirtying its own hands, sends a suspect to a state that engages in the worst kind of torture. For example, despite all the heated rhetoric the US promulgates about Syria, some of the people the US has captured have been sent there to be tortured.
Ashcroft-Gonzales hospital incident
When then-Attorney General John Ashcroft was in the hospital (and under sedation), his deputy found that many of the programs of the Bush administration (possibly including torture) were illegal. Alberto Gonzales, then White House counsel, went to visit Ashcroft in the hospital to try to get him to sign off on the programs. Ashcroft refused, rightfully understanding that he was in no position to sign off on anything, and told Gonzalez to talk to his deputy, who was currently the acting Attorney General. Then, after getting out of the hospital, Ashcroft signed off anyway.
World public rejects torture
A June 2008 international survey of public attitudes to torture is rather depressing for liberal Americans: only 53% think that "All torture should be prohibited". This contrasts with the UK where the figure is 82%. Oddly enough, most of the current techniques used by Americans were developed by the British.
The US falls below states like Ukraine, Poland and Egypt and 13% "think "Torture should generally be allowed". 
An historical aside: In ancient Greece and Rome, and possibly elsewhere, the testimony of a slave could only be accepted by an official tribunal or court after the slave had been tortured. Surprisingly, Greece and Rome were considered at the time to be civilized countries. Of course, pretty much all and every society through out history has considered its self to be the most advanced civilization ever, and you didn't want to be a nubile boy in either Greece or Rome at that time, so . .........
- ↑ http://hrw.org/press/2001/11/TortureQandA.htm
- ↑ http://www.newscientist.com/article/mg18424746.000-does-torture-work.html
- ↑ However, there is increasing evidence that the US, in many cases, directly engaged in torture. They just made sure to do it in gray areas, like Guantanamo.
- ↑ BBC : Rove interview
- ↑ UK forces taught torture methods The Guardian
- ↑ Source of poll data