Are antisemitism and Islamophobia twin sides of the same coin? Or in any way remotely similar? The none-too-subtle insinuation that they are has become commonplace in our media and politics. Prominent Jewish groups have also fallen for it. But they should know that this is a terrible trap.

It is some years since I first remember speaking at a synagogue in this country and hearing from one self-appointed leader of British Jews that in order to tackle antisemitism we must also tackle Islamophobia.

I can see some political sense in such a pose, certainly. But it makes no other variety of sense. First, because there is no agreed-upon definition of what Islamophobia means and, in the absence of this, the word tends to mean, Alice in Wonderland-like, whatever the speaker wishes it to.

To date, the term is loosely and successfully used against critics of anything said or done in the name of Islam. For instance, highlighting what jihadis say when they carry out acts of violence and highlighting that they claim to be inspired for religious reasons is said to be deeply Islamophobic, as we saw with the coverage of the killers of Drummer Lee Rigby. The fact that the killers were quoting Islamic texts and ideas was something politicians and pundits were squeamish about even acknowledging. Which is why everyone went to such pains to say that the actions were not just a bad interpretation of Islam or an extreme interpretation of Islam but as, David Cameron said, had absolutely no connection to Islam, running, in fact, contrary to Islam. When people are fearful of speaking the truth there is nothing else available for them to speak other than such falsehoods.

Of course, there are good reasons for being careful with our language. The vast majority of Muslims have no connection to extremists such as those who beheaded Drummer Rigby. But it remains the case that there is too much violence of action and speech among Muslims worldwide.

For instance, far too many who condemn the killing of a British soldier on British streets will praise or condone the murder of a British soldier on the streets of Kabul or Basra. Or the killing of a Jewish Israeli soldier or civilian absolutely anywhere. The Istanbul Declaration signed in 2009 by some British Muslim leaders condoned attacks on British sailors if they in any way enforced the blockade on Gaza. What worth is a moderate who condemns the killing of a British soldier while condoning the killing of a British sailor?

Of course most Britons, including most British Jews, are sincerely worried about pointing out such facts. This is perhaps one reason why some British rabbis continue to sit on interfaith groups with imams and other Muslim leaders who signed the Istanbul declaration or have long track records of antisemitic and anti-Israel activity.

Among the reasons people are scared is because they are worried - and it is a perfectly understandable worry - that they will end up tarring all Muslims with the same brush. It does not matter how many times people stress the important fact, and fact it is, that most Muslims have no sympathy with the jihadis. The allegation that some phobia is being displayed is always there. As is the disingenuous accusation that Muslims are the new Jews. They are not. The Jews are still the Jews. But the counter-theme now runs through our public life.

The word "Islamophobia" is a crock. A phobia is an irrational fear. Claustrophobia is irrational because small places tend not to kill you. On the contrary, it is highly rational to be afraid of some, though not all, interpretations of Islam. It is rational to be afraid of a Salafist. It is irrational to be afraid of an Ahmadiyya. But there are far more Salafists in the world today than there are Ahmadiyya.

Still, people tend to avoid even discussing this because the allegation insinuates something. People are scared of the charge because, if you are an Islamophobe, you are probably also a racist. Since most Muslims in Britain are of darker coloured skin than most other Britons there is a legitimate fear behind this. Is this not the latest manifestation or simply the most recently acceptable manifestation of some very old hatreds or suspicions? The answer is no. Racism exists but it is not the same thing as concern about portions of Islam. Besides, to claim that Islamophobia is the equivalent of antisemitism or that Muslims are the new Jews you must keep in mind everything other than the facts.

I have seen Jews and non-Jews attacked for Islamophobia for highlighting the tradition of antisemitism that has existed in significant portions throughout Islamic history. So how can anybody, Jew or non-Jew, address the subject of Islamic antisemitism without being accused of Islamophobic? This is something with real-time consequences and problems.

For instance, how can someone hoping to avoid the trap laid down by accusations of Islamophobia possibly hope to deal with the real-life, real-time antisemitism of genocidal antisemitic groups like Hamas? If you object to the seventh part of the Hamas Charter - which says that the "end times" will not come "until the Muslims fight the Jews and kill them, and the Jews hide behind the rocks and the trees, and the rocks and the trees cry out, Oh Muslims, there is a Jew hiding behind me, come and kill him" - are you a phobe? Perhaps not. What if you explain what Hamas explains in its charter, which is that this is a saying of the Hadith of Mohammed? And not just any saying but, as Hamas itself acknowledges, a saying of Mohammed as recorded by Bukhari, which is recognised within Islamic tradition as the most textually accurate collection of Mohammed's sayings.

Now of course there are those who would allege that, because Mohammed said this, it is something that all or most Muslims believe or want to act out, and can be blamed for. It is no such thing. Most Muslims noticeably do not go around massacring anybody and it is wrong as well as rude to pretend otherwise. But the problem does exist. And attempting to ignore it or cover it over simply exacerbates the problem on all sides. It makes life easier for the jihadis and their fellow travellers who want a free pass. And it exacerbates the anger of non-Muslims who recognise that there are problems within Muslim communities that need to be dealt with.

But fearing the accusations of Islamophobia that will come their way if they tackle this, most people increasingly just avoid dealing with these issues. Such avoidance and fear is convenient for the extremists. It is what they hope for and is the best enabler we can give them.

But even if there were not the problem of Islamic antisemitism, how could it be that antisemitism and Islamophobia could be equated? Antisemitism is hatred of the Jews as people. Islamophobia, in so far as there is any definition available, is anything that any person who is Muslim regards as being so. It is one of those post-Macpherson crimes: in the eye of the beholder. And we are collectively highly vulnerable to it.

When an organisation called Tell Mama said, after the murder of Drummer Rigby, that there had been an unprecedented backlash against British Muslims, they got huge public attention. They succeeded in taking attention away from the real story: the decapitation of a soldier in Woolwich. And they pushed a narrative that although Muslims must not be held responsible en masse for such an atrocity, the rest of us are in fact a gang of barbarians just poised for an anti-Muslim pogrom. This is thankfully not the case. But it should not have taken the Sunday Telegraph to expose the fact that more than half of the uncorroborated claims of anti-Muslim assaults highlighted by Tell Mama consisted of unpleasant things said online, not necessarily even from within the UK.

Jews know from the work of the CST and others what actual peaks of antisemitic violence look like, as well as where they come from. This makes Jews perhaps even more vulnerable than most to believing the claims being opportunistically made by some British Muslims.

I sometimes think that, for Jews, there is no way out. They have been attacked for their victories and disasters, their poverty and their wealth, their difference and their sameness. No survey of the history of antisemitism can fail to conclude that it often seems, at least in part, nearly ineradicable as a human sickness.

What is often called Islamophobia, on the other hand, is eminently solvable. Indeed, any real upsurge in suspicion or criticism of Islam can be stopped in an instant. For, if any suspicion of Muslims does exist it comes not because of some phantom but because of the behaviour of Islamic extremists, not least their genocidal and ongoing war against Jews. If Muslims can eradicate the sickness of extremism, such as antisemitism, from their faith then Islamophobia will become not only an unsatisfactory word, but a wholly un-needed one.

Douglas Murray is the author of 'Islamophilia: a very metropolitan malady' (emBooks)