I agree that we currently face a major threat, not just from Jihadis, but from the rise of Islamicism in general - Islamicism as I understand it being the attempt or the wish to impose Islamic views and behaviour on others, this petition being a fine example.
And I actually think that yes it is crucial to criticise and mock Islam, and any other religion which supports or can be used to support oppressive behaviour.
If people in the west had not had the courage to criticise and challenge Christianity in the past, we would never have had the relatively free society we have today. (Of course it's very imperfect, but compared to what I see of most Muslim societies, it seems pretty damn good.)
We need to be really vigilant if we want to conserve the freedoms and equalities that have been so hard fought for in the UK and other European countries.
And yes, there are indeed Muslims who are not only not offended by the cartoons, but who actively wish people to continue these kinds of criticisms and challenges of their own religion. Because they too cherish freedom and equality.
Iram Ramzan is one, and she wrote an excellent piece in the wake of the Paris murders, which I am quoting liberally from here:
Many people criticising the cartoons have been conflating racism with criticism of religion. The former is abhorrent and we have laws against this. The latter is perfectly legitimate.
We should remember that European enlightenment was a product of centuries of challenges to religious authority, after which secularism was able to flourish. That is one of the reasons why reactionaries abandon the Muslim world: silenced in their own countries, they seek refuge in the liberal West, only to undermine its principles from within.
What we need is for people to continue to blaspheme, else we will be complicit in the Islamists gaining strength and destroying us all. They are organised, determined and, armed with deadly weapons and the belief that they have a divine power on their side, they will prevail.
Dissenting voices I have come across with Muslim communities have expressed fear for the future. If we do not defend our rights and freedoms then, to paraphrase Pastor Niemöller, one day there will be no one left to speak for us.
It's an excellent and courageous article and well worth reading in full here. It was written before this petition, in the wake of the Paris murders, and actually starts from the point that in the furore about the cartoons/provocation angle, the fact that four people were murdered simply for being Jewish has been almost completely ignored.
She has links on her blog to other "dissenting voices". As a left wing non Muslim myself who's increasingly concerned by some of the rhetoric of the left - the idea that saying anything negative about Islam or any Muslims is racist and Islamophobic - it's a breath of fresh air to find these voices.