"If someone commits a crime and a greater crime arises from it, they are guilty of that greater offense as well."

Is this true? Certainly, if two people walk in to a bank, guns drawn, to commit an armed robbery that ends in murder, both are responsible no matter who actually pulled the trigger.

But is the person who illegally sold the two armed robbers the gun (without knowing what they planned to use it for) also responsible for any murders they commit? I'm not a lawyer, but I don't think they are. Yet can it not be said that the bank robbery/murder arose from the first crime of illegally purchasing/selling a gun? It certainly enabled them to commit the crime.

After all, as others have pointed out, there are prostitutes who are not trafficked, and their transaction is legal; and, pace AlecsMom, I fail to see anything demeaning in paying someone for a voluntary service exchanged between consenting adults (which is what prostitution ultimately is--there is no 'sale of the body' since the body remains with its rightful owner). The real problem is really trafficking and people forced to work against their will (the analogy being the sweatshop).

If I buy a shoe, I may eventually in some sense be an accomplice in the exploitation of those who made the shoe; but this sense is at best very indirect, especially since there are shoes also made without exploitation and, barring documentation of sources, there usually is no way I could know whether this shoe was or was not made in such a way. It should be up to the authorities not to allow 'exploitive shoes' to enter the market; but unless they are somehow marked, no customer is going to be able to tell them from shoes made without exploitation (the shoe shop certainly will claim they are 'good'). The same goes for prostitution: it's up to law enforcement to make sure all prostitutes are legal and consenting (thus non-trafficked; i.e. legalization, decriminalization and regulation), not to the john who may be purchasing a service from a trafficked person, but may also be purchasing it from a consenting professional--and there's no way he can tell the difference (both will tell him the same story) unless there is a legal certificate.

Perhaps you simply lack information. In a PA suburb, we had a recent case of two young Asian women lured to the US under false pretenses of legitimate work. Once in the custody of their captors, it became clear to the women that they were to work as prostitutes. One of their captors was a woman. The two women escaped and sought help. The woman and her accomplice(s) have been arrested and all of the women have been granted status to remain in the country as trafficked victims.

Question 1: How is that hard to prove? You have witnesses. You have a brothel location. You have perps. One will no doubt roll on the other.

Question 2: Why shouldn't the men who purchased the sexual services of the victims be prosecuted for rape? Is it really a credible defense that these men didn't know that the women were trafficked or did they think this was an great way for foreign-born Asian girls to spend their time and make money?

Ask yourself what makes sense. If someone commits a crime and a greater crime arises from it, they are guilty of that greater offense as well. I'm not saying that every john should go to jail, but that every john who purchases sex should be aware that they may be complicit in sexual slavery. Ignorance is not nor should it be a defense in this case.

There is no philosophical argument here. The fact is that all Johns commit a crime (where it is illegal). The question is whether they are complicit in far greater crimes. The evidence from experts in the area of trafficking strongly suggest that they are. I don't respect anyone who purchases sex since I see it as an exploitative act but that doesn't mean I want to fill jails with ordinary guys.

However, if in the course of an investigation it is discovered that the prostitute is underage or trafficked, I would be perfectly satisfied to see all the johns who are caught to be prosecuted to the harshest degree possible under the law. It's very simple. These men are culpable in rape. That's just what it is. These men don't deserve a pass because they were unable or unwilling to use common sense. That's the same as a person being accused of receiving stolen property and claiming, "I didn't know that Rolex wasn't his!" Really??? Should stupid and uncaring be a defense?

The greatest opposition against prostitution has always come from the right-wing. Sex-positive feminists like Paglia or Wendy McElroy have always favored prostitution (see McElroy's book XXX)--you're accusing the wrong group here.

You're thinking of the American right-wing. This proposed legislation is in the UK, and it's being proposed by feminists and liberals within the Labor government, not by a bunch of archconservatives.

Even in America, your argument is pretty forced. Feminist crusaders in the 19th and early 20th centuries were most definitely anti-prostitution, and modern feminism has been, at the very least, deeply divided on the question. Paglia and McElroy are no more representative of feminism than Dworkin and MacKinnon are. Sex-positive, pro-porn, pro-sex work feminists have always been pitted against sex-negative, anti-porn, anti-sex work feminists. The former group may have started to win out in the last 10-20 years, but I wouldn't go so far as to say their victory has been decisive or final.

The UN reports make it clear that in locations where prostitution is legal, violence against all women goes up...

Oh, so then Canada and countries such as the Netherlands in Western Europe have higher rates of rape, sexual assault, and domestic violence than the US does?

I find that very hard to believe. Please back up your assertion with solid, convincing evidence.

A rape charge would be contested vigorously in court and the conviction would depend on proving a woman "is trafficked or under the control of a pimp or drug dealer". That would inevitably put the girl on trial - is she physically or mentally controlled? Is she unable to escape from her situation? What choices has she made to put herself in her work?

Claims are made over 95% of sex workers are trafficked or controlled. How many cases would actually stand up to cross-examination in court?