ISIS-related sentences keep getting stiffer. Can they be prevented?

A 22-and-a-half-year sentence seems to be the going punishment for an American convicted of recruiting impressionable radicals to Islamic State (IS, also referred to as ISIL).

The US Attorney for the New York state district called American Mufid Elfgeeh "one of the first ISIL recruiters ever captured," but his lengthy sentence is not the first record penalty a US court has handed down for IS involvement, Julia Harte reported for Reuters. In May, a federal judge in North Carolina gave Donald Ray Morgan 20 years and three months for unlawful firearm possession and trying to provide material support to IS.

These two sentences are the harshest ever given for such offenses, Reuters and the US Justice Department reported. They may continue, as an Arizona jury on Thursday convicted another man of conspiring to support IS, joining two unrelated convictions in Ohio and Mississippi the same week.

These harsh penalties may demonstrate to IS sympathizers that the US justice system investigates and prosecutes terrorism seriously in order to provide a strong deterrent. Deterrence is an important, but difficult-to-measure aspect of prevention. Some counterterrorism organizations and Muslim Americans are formulating other, more proactive approaches.

"The number of ISIS recruits in America and the complex scene they comprise poses a challenge that cannot be solved solely by arrests," according to "ISIS in America: From Retweets to Raqqa," a detailed study from George Washington University's Center for Cyber and Homeland Security released in December. "Law enforcement vigilance is vital but insufficient on its own."

One suggestion involved granting disillusioned IS fighters limited immunity in return for sharing their reasons for leaving the group, as their on-the-ground credibility might persuade many to rethink a defection to the Islamic State fighting force in Syria. By way of international comparison, this approach proved effective for Indonesian officials dealing with a widespread terrorist threat.

Members of America's Muslim community also want to help. Several told researchers they could counter extremists online using Islam-friendly rhetoric, but they were afraid the FBI might begin investigating them simply for contacting the prospective radicals.

One such individual is Yasir Qadhi, a professor of Islamic studies at Rhodes College in Memphis, who told The Christian Science Monitor's Warren Richey he wants to leverage his influence to talk young Muslims off the path of radicalization. But after being investigated by the FBI post-9/11, he is wary.

As a respected and relatively young Islamic authority, he is regularly approached by young Muslims struggling with whether to answer the Islamic State group’s call to arms.

“I have had and will continue to have lots of dialogues with young men,” Qadhi says. “I am happy to say that none of the people I’ve spoken to about these issues has gone overseas.”

Most families would want to work with law enforcement if their children show signs of radicalization, The Christian Science Monitor found. Most say they would rather see their son or daughter behind bars than dead in Syria, although some want to find a third path – a way out of radicalization.

Christianne Boudreau, a Canadian mother, was "both devastated and furious" when she discovered only after it was too late that authorities had spent two years investigating her son's involvement with IS. She and others are working to provide families with resources to counteract loved ones' radical tendencies before they become illegal actions, possibly punishable by a 22-year jail sentence.

“[IS recruiters] have recruiting manuals that are so sophisticated that the only thing we can do is build up the family or the social environment as a counterforce,” Daniel Koehler, director of the Berlin-based German Institute on Radicalization and De-radicalization Studies, told The Christian Science Monitor. “That is the only way we can succeed.”