The West has become too tolerant of Islamic fundamentalism. There must be a limit to freedom of speech and to the spread of crazy ideals that justify the killing of other human beings. I have many friends who are tolerant Muslims, but I always criticise them for not doing enough. Sometimes they seem to side with the bombers and believe in their hearts that what they are doing is justified in the name of Islam. We must accept the fact that sometimes one cannot respect other people's beliefs if they justify murder, and the teachings and messages being spread to Muslims in the West must be monitored more closely. Name withheld, Birmingham

Many of the comments and articles trivialise these terrorist attacks and their significance. Terrorism does not exist as the action of a few "marginalised extremists" or "misguided criminals". It is a virulent ideology nurtured by communities. Terrorism, especially of this sophistication, requires the support of a community. Almost certainly, the majority of Muslims do not support it, but a substantial number must do. Community support in hiding evidence, securing finance and training is the necessary lifeblood of terrorists. Without it they cannot exist. Karen Wilson, London

It is a grave error to suppose that any nation can exist without having a set of unifying cultural values at its core that all members, no matter how diverse their race or religion, readily adhere to. The Muslim community must learn to separate state and religion, and to subordinate personal grievances to the well-being of society - a vision that should conform to the free and tolerant British way of life. Robert Farrell, New York

It must be very distressing for some parents to send their children to university in good faith, only to have them return home with extremist views and more conservative values than those held by the family. I have personally known two such youngsters and heard of several others who were recruited into Islamic societies while at universities here in England. The most extreme case was of a 20-year-old, who insisted his sisters should cover their heads with a hijab and keep the curtains of the house drawn at all hours so that no man could lay eyes on the women of the house. It may be argued that the parents could refuse to fall in line with such views, but it is an accepted fact in Asian society that the sons of the house must be respected. Some parents are very proud to have children who have turned out like this and brag about their virtuous child and happily take credit for bringing up and inculcating such high morals. Whether they realise that one day these children may take drastic measures and cause harm to others is debatable. If they still don't do something about it after the atrocities in London then each and every one of them ought to hang their heads down in shame. Name and address withheld

Terrorists want to destroy us by changing us. Simple as that. Just as they have no values, they want us to abandon the principles that we value. If we do not allow them to beat us, then they will join us. Let's not lose hope. Let's frustrate them instead. Of course, we mustn't give up chasing them. We have to let them know that we will not tire in bringing them to justice. Z. Hussain, Rochdale

Would I be correct in saying that it is not an Islamic world the bombers want but an Arab one? If the Koran believes that killing is a sin, then I believe that it must be a cultural change and not a religious one that these murders seek. Raymond Alderton, Exeter

Terrorism is now a part of our lives; the important thing is to make it clear to the terrorists that it is the wrong way to go. I'm very proud of how the British have answered this attack - much better than the Spanish putting blame and responsibility on each other. Javier Peña, Seville, Spain

Liberals and Muslims have been quick to blame everyone but the Muslim community for these atrocities. I am a second generation immigrant of African descent. Nobody has made the point that black youths, and indeed many white youths, are disaffected and marginalised. However, their coping strategy (thank God) is not terrorism. Before someone trots out the tired excuse of atrocities around the world being a trigger, let me remind you that black Africans have suffered more than any other people in history and yet have always remained peaceful. It seems that there is something specifically more unstable about Muslim immigration and this does not bode well for the future of Britain. Name and address withheld

The British Government is partly to blame for the atrocities. Why? Because radical Islamic groups are free to distribute circulars and other materials outside mosques promoting hatred and rasicsm. They can't do it inside the mosque because most Muslims don't accept their crazy misinterpretations of the Holy Koran. Every Friday prayers you'll see them distributing thier sick concept of Islam and encouraging people to join the movement. They believe that jihad is to fight the unbelievers, even if it means to dying for the cause. True Islam does not condone such acts; it encourages us to know our neighbours and to treat everyone with respect. People must do their bit to help the British Goverment to eradicate this menace by identifying these extremists and flushing them out. David Hamid, Damascus, Syria

There is a clear responsibility now for the security authorities, the Muslim leaders and the Muslim community to work together to infiltrate and expose those hotspots of religious fundamentalism which interpret and distort the teachings of the Koran. This preventative measure needs to be seen by the wider community as a willing attempt by Muslims to flush out those people who are capable of harming the peaceful and tolerant society we value so much. Keith Downer, London

Unction and piety and pretending that all of the new "communities" in Britain are really just like us is the worst sort of limp liberalism. The last thing we need is for more deference to their demands that we become like them. Instead, English values need asserting more strongly so that they become like us. If they will not accept that then the question "but why are you here?" naturally follows. Name and address withheld

The leaders of the Islamic community in Britain should be more pro-active in undermining the doctrine of the fundamentalist clerics who instil the sense of martyrdom and promise of afterlife in paradise in the suicide bombers. Presently, they condemn actions after the event, rather than challenge the credibility of the clerics' interpretation of the Koran, while recruiting tomorrow's bombers. For no other reason, it will diffuse the problem of a backlash against innocent members of the Muslim community, evidence of which has started to surface after the London bombings. Michael Sleddon, Leamington Spa

You seem anxious to avoid stigmatising British Muslims for the gruesome acts of 7/7, and yet that is what your leader does. You ask of the London bombers: "And how were they able to keep their deadly plans secret, without arousing suspicion among their families, neighbours or fellow Muslims?" You imply families, neighbours and fellow Muslims must indeed have known of their plans by demanding that "The law-abiding majority must recognise a responsibility to end the cult of nihilistic extremism..." This demands a responsibility on Muslims that does not apparently apply to the relatives of other criminals whose actions, though not causing damage on the same scale, are no less complex to plan. Of course, the police must investigate whether anyone in the UK, outside the bombers and those supplying the bomb material, knew of the plot. But why should you assume that Muslims are not subject to the same looser or dysfunctional family ties that afflict society as a whole? I would no more assume this than I would blame the families of serial killers for their "failure" to deliver up their black sheep. Peter Bild, Berlin, Germany