A spate of recent terror attacks in the US and Canada underscore the danger of so-called "lone wolf" terror attacks that appear to be on the rise in the West.

A gunman stormed Canada's parliament in Ottawa on October 22 after killing an unarmed ceremonial guard outside the building and was later shot dead. The incident followed a recent attack whereby a man purposely rammed his car into two Canadian soldiers near Montreal, killing one of them.

Also on October 23, four New York City police officers were attacked in broad daylight by a hatchet-wielding assailant. And in September a man in the state of Oklahoma beheaded a coworker.

In all these cases, the attackers were allegedly recent converts to Islam. While information is still trickling out, the attacks appear to be acts of terror, highlighting the danger the West and North America are facing from "lone wolves" who hold radical views.

From a law-enforcement standpoint, "lone wolves" are nearly impossible to preempt. They do not belong to terror cells, which precludes the possibility of law enforcement infiltrating the groups or monitoring their movements. Attacks can usually be stopped only when they are already in progress, experts say.

Rather than taking orders from superiors, homegrown radicals are influenced by the hateful ideology spewed by terror groups including Al Qaeda and the Islamic State (IS). The latter has in recent months overrun vast swaths of territory in Iraq and Syria.

In his book entitled A Battle for the Soul of Islam, author Zuhdi Jasser noted that several US-born Muslims or naturalized US citizens have plotted to attack the US.

Other US radicals have traveled overseas to link up with groups such as the IS, part of a trend of Western nations' citizens joining up with terrorist groups abroad. Jasser said that it is Islamist supremacist ideology, rather than political events and grievances, that drives Islamist terrorism.

In a recent speech, US President Barack Obama said the White House aims to tackle the extremist ideology that has inspired so much violence, although some are skeptical over whether the US can have an impact.

Wayne White, former deputy director of the US State Department's Middle East Intelligence Office, said that it would be difficult for Washington to battle the spread of such ideology, as the US is perceived by many in the Muslim world as a "Christian" country.

Moreover, the invasion of Iraq, US support for Israel and ongoing drone strikes in Muslim countries are widely unpopular in the Islamic world.

"Washington's ability to address the overarching issue of Islamic radicalism is extremely limited," White said.

The author is a writer with the Xinhua News Agency. opinion@globaltimes.com.cn