I hate to break it to you, but the Qur'an is not written in chronological order. Other than that, the Qur'an also has the downside (or advantage, depending on the situation and on how you look at it) of being decidedly vague on a lot of things, and having an absurd amount of verses that seem to refer obliquely to some particular event, without it being very clear what exactly they refer to. The result is that the Qur'an is extremely open to interpretation, even by the standards of religious books. And the theory of later verses superseding earlier ones - assuming that one can even be sure about which verse is later, which is also not always clear - is merely one possible view of how to reconcile seeming contradictions.

In any case, though, there's very little in the Qur'an that really condones violence (most of the violent things usually quoted as proof come from the hadith), and on the topic of murdering innocents in peacetime, you'd have to look very far and stretch very far to find a justification.

Most importantly of all, though, there is no single "Islam" in much the same way there is no single "Christianity". An uncomfortably large number of Muslims condones violence in at least certain circumstances, even if those condoning real terrorism are few and far between, that's true. But if you say that "Islam does in fact condone and call for violence", you're suggesting that the many Muslims who do not are somehow doing it wrong, or are not real Muslims. And that is most definitely very wrong.

Wikipedia has some nice "Reactions to (insert name of big event)" pages, so it's not as if this requires serious research. I'll even leave in the reactions that did condone violence, so that you can feel you're not entirely wrong (which of course is the case). Below is about the 2005 London bombings.

The Grand Mufti of Saudi Arabia, Sheikh Abdul Aziz Al-Asheikh denounced the deadly blasts that rocked London, saying ""Killing and terrorising innocent people and the destruction of property are not condoned by Islam". He also censured the terrorists for tarnishing the image of Islam by attaching their heinous crimes to the religion.[73]
The Muslim Council of Britain said that it "utterly condemns" the "indiscriminate acts of terror".[74]
The Australian Muslim Civil Rights Advocacy Network have issued a public statement condemning the attacks, offering their condolences to the British people, and pledging their support in bringing the terrorists to justice.[75]
The Council on American-Islamic Relations condemned the attacks, stating "We join Americans of all faiths, and all people of conscience worldwide, in condemning these barbaric crimes that can never be justified or excused. American Muslims offer their sincere condolences to the loved ones of those who were killed or injured in today's attacks and call for the swift apprehension and punishment of the perpetrators".[76]
The Islamic Circle of North America released a statement saying, "The Islamic Circle of North America (ICNA) is shocked and horrified at the several attacks on the people of London during the rush hour mass transit. We join everyone in condemning such acts of terror and senseless violence. Our thoughts and prayers are with the victims and their loved ones at this tragic moment. We trust that the authorities will determine those responsible for these barbaric acts and bring them to justice quickly".[77]
Leading Lebanese Shi'ite Muslim scholar Mohammad Hussein Fadlallah stated, "These crimes are not accepted by any religion. It is a barbarism wholly rejected by Islam."
Many Muslim Britons were deeply hurt and disgusted at these attacks, especially due to the fact that the bomb site by Aldgate station had a huge surrounding Muslim and Asian community. However, they cited the British government foreign policy as the main reason for the attacks. One in four British Muslims supports the reasons mentioned by the terrorists.[7
Al Qaeda cleric Omar Bakri Mohammed approved of the bombings and called them a "warning" for the British government.[79]
The cousin of Shehzad Tanweer, one of the suicide bombers, approved of the suicide bombings by Tanweer and called him a "good Muslim".[80]
About 2,000 villagers in Shehzad Tanweer's Pakistani village of origin prayed for him at his funeral.[80]
Grand Imam Mohammed Sayyed Tantawi of Cairo's Al-Azhar University condemned the attacks and said that the attacks could be not justified as an attempt to force Britain out of Iraq. "This is illogical and cannot be the motive for killing innocent civilians".[81]

Oh, and I also came across this, because as they say a picture says more than a thousand words.

And if you like catchy tunes, this became a massive #1 hit in Pakistan a few years ago in the best We Are the World tradition. The lyrics are admittedly somewhat obscure, but the message at the beginning of the video is clear enough, I trust.