There is only one view of the murder of the British soldier Lee Rigby on a south London street three weeks ago: Horrific. But there are two views of its significance. One is that it was an act by crazy people, motivated in this case by a perverted notion of Islam, but of no broader significance.
Crazy people do crazy things, so don't overreact. The other view is that the ideology that inspired the murder of Rigby is profoundly dangerous.
I am of the latter view. Of course, we shouldn't overreact. We didn't after the July 7, 2005 attacks on London's public-transport system. But we did act. And we were right to do so.
Our security services' actions undoubtedly prevented other serious attacks. The "Prevent" programme in local communities was sensible.
The government's new measures seem reasonable and proportionate as well. But we are deluding ourselves if we believe that we can protect the UK simply by what we do at home. The ideology is out there. It is not diminishing.
Consider the Middle East. Syria now is in a state of accelerating disintegration. President Bashar al-Assad is brutally pulverising entire communities that are hostile to his regime. At least 80,000 people have died, there are almost 1.5 million refugees, and the number of internally displaced people has risen above four million. Many in the region believe that Mr Assad's aim is to cleanse the Sunni from the areas dominated by his regime and form a separate state around Lebanon. There would then be a de facto Sunni state in the rest of Syria, cut off from the country's wealth and access to the sea.
The Syrian opposition comprises many groups. But the fighters associated with the al-Qaeda-affiliated group Jabhat al-Nusra are generating growing support _ including arms and money from outside the country.
President Assad is using chemical weapons on a limited but deadly scale. Some of the stockpiles are in fiercely contested areas.
The West's overwhelming desire to stay out of it is completely understandable. But we must also understand that we are at the beginning of this tragedy. Its capacity to destabilise the region is clear. Jordan is behaving with exemplary courage, but there is a limit to the number of refugees that it can reasonably be expected to absorb. Lebanon is now fragile, as Iran pushes Hezbollah into the battle. Al-Qaeda is again trying to cause carnage in Iraq, while Iran continues its meddling there.
Meanwhile, in Egypt and across North Africa, Muslim Brotherhood parties are in power, but the contradiction between their ideology and their ability to run modern economies has fuelled growing instability and pressure from more extreme groups.
Then there is the Iranian regime, still intent on getting a nuclear weapon, and still exporting terror and instability. In Sub-Saharan Africa, Nigeria is facing gruesome terror attacks. In Mali, France fought a tough battle to prevent extremists from overrunning the country.
Then there is Pakistan _ and Yemen. Farther east, a border war between Myanmar and Bangladesh is simmering. And recent events in Bangladesh itself, or in the Muslim-majority Mindanao region of the Philippines, extend the list further.
In many of the most severely affected areas, one other thing is apparent: A rapidly growing population. The median age in the Middle East is in the mid-20s. In Nigeria, it is 19. In Gaza, where Hamas holds power, a quarter of the population is under five.
When I return to Jerusalem soon, it will be my 100th visit to the Middle East since leaving office, working to build a Palestinian state. I see first-hand what is happening in this region.
So I understand the desire to look at this world and explain it by reference to local grievances, economic alienation, and, of course, "crazy people". But can we really find no common thread, nothing that connects the dots of conflict, no sense of an ideology driving or at least exacerbating it all?
There is not a problem with Islam. For those of us who have studied it, there is no doubt about its true and peaceful nature. There is not a problem with Muslims in general. Most in Britain are horrified at Rigby's murder.
But there is a problem within Islam, and we have to put it on the table and be honest about it. There are, of course, Christian extremists and Jewish, Buddhist and Hindu ones. But I am afraid that the problematic strain within Islam is not the province of a few extremists. It has at its heart a view of religion _ and of the relationship between religion and politics _ that is not compatible with pluralistic, liberal, open-minded societies. At the extreme end of the spectrum are terrorists, but the world view goes deeper and wider than it is comfortable for us to admit. So, by and large, we don't admit it.
This has two effects. First, those who hold extreme views believe that we are weak, and that gives them strength. Second, those Muslims _ and the good news is that there are many _ who know the problem exists, and want to do something about it, lose heart.
Throughout the Middle East and beyond, a struggle is playing out. On one side, there are Islamists and their exclusivist and reactionary world view. They comprise a significant minority, loud and well organised. On the other side are the modern minded, those who hated the old oppression by corrupt dictators and despise the new oppression by religious fanatics. They are potentially the majority; unfortunately, they are badly organised.
The seeds of future fanaticism and terror _ possibly even major conflict _ are being sown. Our task is to help sow the seeds of reconciliation and peace. But clearing the ground for peace is not always peaceful.
The long and hard conflicts in Afghanistan and Iraq have made Western powers wary of foreign intervention. But we should never forget why these conflicts were long and hard: we allowed failed states to come into being.
Saddam Hussein was responsible for two major wars, in which hundreds of thousands died, many by chemical weapons. He killed similar numbers of his own people. The Taliban grew out of the Soviet occupation of Afghanistan and turned the country into a training ground for terror. Once these regimes were removed, both countries began to struggle against the same forces promoting violence and terror in the name of religion everywhere.
Not every engagement need be military, and not every military engagement must involve troops. But disengaging from this struggle won't bring us peace.
Neither will security alone. While revolutionary communism was resisted by resoluteness on security, it was ultimately defeated by a better idea: Freedom. The same can be done here. The better idea is a modern view of religion and its place in society and politics _ a model based on respect and equality among people of different faiths. Religion may have a voice in the political system, but it must not govern it.
We have to start with children, here and abroad. That is why I established a foundation whose specific purpose is to educate children of different faiths around the world to learn about each other and live with each other. We are now in 20 countries, and the programmes work. But it is a drop in the ocean compared with the flood of intolerance taught to so many.
Now, more than ever, we have to be strong, and we have to be strategic. 2013 PROJECT SYNDICATE
Tony Blair was prime minister of the UK from 1997 to 2007.
About the author
Writer: Tony Blair