[See also "The Alien In Hokie Nation"—Buchanan On The Dark Side of Diversity, about an earlier Immigrant Mass Murder at Virginia Tech.]
Yet, some assertions appear true.
Islam is growing in militancy and intolerance, evolving again into a fighting faith, and spreading not only through proselytizing, but violence.
How to justify the charge of intolerance?
The Taliban blew up the Bamiyan Buddhas. The Sufi shrines of Timbuktu were blown up by Ansar Dine. In Saudi Arabia, Iran and Afghanistan, Christian converts face the death sentence.
In Nigeria, the Boko Haram attacks churches and kills Christians, as in Ethiopia and the Sudan, where the south seceded over the persecution.
Egyptian Copts are under siege. Assyrian and Chaldean Christians in Iraq have seen churches pillaged, priests murdered. In Indonesia, churches are being shut on the demand of Islamists. Sharia law is being demanded by militants across the Middle East, as Christianity is exterminated in its cradle.
Has Islam become again a fighting faith?
Chechnya, Dagestan and Ingushetia are the sites of Islamist uprisings using terror to rip these statelets from Russia. Muslim Uighurs are fighting to tear off a chunk of China and create an East Turkestan. Muslim Malays in south Thailand have fought a decade-long war of secession. Albania has acquired two sister Muslim states in Europe, Bosnia and Kosovo, both born in blood.
At the time of 9/11, al-Qaida seemed confined to Afghanistan. Al-Qaida may now be found in the Maghreb, Mali, Iraq and Yemen. Its Syrian auxiliary, the al-Nusra Front, is dominant in the anti-Assad rebellion.
Since Y2K, Islamists have perpetrated massacres in Mumbai, Madrid, London, Moscow, Beslan and Boston. Osama bin Laden appears no longer as popular as he once was, yet tens of millions worldwide still admire him. Why?
Islamism can also call upon true believers prepared to die for the cause. No other faith produces so many suicide bombers.
Muslims counter-argue that America has killed many more noncombatants, in Iraq, and Afghanistan and Pakistan with drone strikes.
What right, they ask, did we have to attack Iraq? Did we not ourselves stir up the nest of hornets that stung us in Boston?
Yet there is another reality.
While the clash of cultures widens between the West and Islam, leaders in the Muslim world can be found working with the United States against their own extremists.
Jihadists are by no means a majority in the Islamic world, where they are also feared and hated. And in the West, they are but a fraction of our Muslim communities.
The crisis: Even a tiny minority of terrorists like the Tsarnaevs can so inflame tensions between the West and the Muslim world they can bring our two civilizations into conflict. Would we have fought those wars in Iraq and Afghanistan without the atrocity of 9/11?
What are the goals of the jihadists?
Expulsion of Christians and infidels from the Dar al-Islam, the house of Islam. Expulsion of the American Crusaders. Overthrow of Muslim rulers who collude with the Great Satan. Annihilation of Israel. Infiltration of the homelands of a decadent, dying West. Death to all who insult the Prophet.
Ultimate goal: Bring the world to acknowledge and act on the truth that there is no God but Allah and Muhammad is his Prophet.
And while the Islamic world remains far inferior in technology and manufacturing and military power, Muslim peoples are far more numerous and devout. With a fourth of mankind, their birth rate is higher and their numbers soaring, along with their militancy at home and in the diaspora.
In population and territory, the West is shrinking, while our Muslim minorities are growing and becoming more assertive in their demands.
"No army can withstand the strength of an idea whose time has come," said Victor Hugo. Many in the Muslim world believe that as the Christian West dominated for 500 years, their time has come.
How do we deal with this irreconcilable conflict between a secular West and a resurgent Islam?
First, as it is our presence in their world that enrages so many, we should end our interventions, shut down the empire and let Muslim rulers deal with Muslim radicals.
Second, we need a moratorium on immigration from the Islamic world. Inevitably, some of the young we bring in, like the Tsarnaevs, will yield to radicalization and seek to strike a blow for Islam against us.
What benefit do we derive as a people to justify the risks we take by opening up America to mass migration from a world aflame with hatred and hostility over race, ethnicity, culture, history and faith?
Why are we bringing all of the world's quarrelsome minorities, and all the world's quarrels with them, into our home?
What we saw in Boston was the dark side of diversity.
Patrick J. Buchanan needs no introduction to VDARE.COM readers; his books State of Emergency: The Third World Invasion and Conquest of America, and Suicide of a Superpower: Will America Survive to 2025? are available from Amazon.com