One of the two London butchers, Nigerian-born Michael Adebolajo, was radicalized by the cleric Abu Hamza al-Masri, who headed the outlawed terrorist group Al-Muhajiroun.
The group follows Wahhabist teachings and advocates unifying all Muslims, forcibly if necessary, under a single fundamentalist theocratic government.
Similarly, the Boston bombers, Tamerlan and Dzokhar Tsarnaev, hailed from Russia’s southern predominantly Muslim province of Chechnya. Starting in the late 1980s, Saudi Arabia began dispatching Wahhabist clerics and radical preachers to Chechnya.
The spread of Wahhabism sparked not only a separatist war against the Russians, but also a good deal of violence among Muslims.
Wahhabism is now institutionalized in Chechnya and is particularly attractive to young men.
There are similar strands leading back to Wahhabist indoctrination in the histories of very many of the known Muslim terrorists of the last 20 years.
The founder of the sect, Muhammad ibn abd al-Wahhab, was an eighteenth century Muslim zealot allied to the Al-Saud clan who promoted an extreme version of Salafism.
Salaf is the Arab word meaning pious ancestor and refers to those who attempt to emulate the pure Islamic life of the Prophet Muhammad and his generation of followers.
But Wahhab and his modern disciples take this notion to extremes. The list of people whom Wahhabists should consider their enemies includes not only Christians, Jews, Hindus and atheists, but also Shiite, Sufi and Sunni Muslims.
And yet no western politicians seem prepared to accept the obvious.
The chances of disaffected young men being drawn into the evil web of Wahhabist murderous extremism would be significantly decreased if the Saudi funding was blocked.
The Saudis began exporting Wahhabism in the early 1970s when the country’s oil wealth began growing at an ever-increasing rate.
The amount the Saudi royal family, both by government donations and the generosity of individual princes, now lavishes on Wahhabist schools, colleges, mosques, Islamic centres and the missionary work of fundamentalist imams around the world is extraordinary.
In 2003, a United States Senate committee on terrorism heard testimony that in the previous 20 years Saudi Arabia had spent $87 billion on promoting Wahhabism worldwide.
This included financing 210 Islamic centres, 1,500 mosques, 202 colleges and 2,000 madrassas (religious schools).
Various estimates put the amount the Saudi government spends on these missionary institutions as up to $3 billion a year.
This money smothers the voices of moderate Muslims and the poison flows into every Muslim community worldwide.