9/11 is one of the hinge events in American history. Understandably Americans therefore tend to filter the concept of "terrorism" though the lens of jihadist terrorism.
Saturday's massacre at a Jewish synagogue in Pittsburgh reminds us that political violence, partly enabled by the most permissive gun laws in the West, is a recurring plague in the United States.
2018 Pittsburgh synagogue attack
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If the series of bombs mailed this past week to multiple leaders of the Democratic Party, CNN and to prominent Jewish philanthropist George Soros was not reminder enough, now we have the tragedy in Pittsburgh that reminds us that lethal anti-Semitism is a feature of American domestic terrorism. According to a statement from the Anti-Defamation League, the killings were "the deadliest attack on the Jewish community in the history of the United States."
Since 9/11, 18 people have been killed in anti-Semitic attacks in the United States.
In 2002, Egyptian-American Hesham Mohamed Hadayet shot up the ticket counter of the Israeli airline El Al at Los Angeles International Airport, killing two people before an airline security guard shot him dead.
The same year, Pakistani-American Naveed Haq killed a woman at a Jewish community center in the Seattle area and wounded five others.
In 2009, James W. von Brunn, a white supremacist, killed a security guard at the US Holocaust Memorial Museum in Washington DC.
Five years later, Frazier Glenn Cross, shouted "Heil Hitler" after killing three people -- two at the Jewish Community Center in Kansas City and one at a Jewish retirement community nearby.
Now comes Saturday's massacre near Pittsburgh in which at least 11 people were killed by Robert Bowers, who made anti-Semitic statements during the shooting, according to law enforcement officials who spoke to CNN.
Bowers blamed Jews for the migrant caravan that is now moving through Mexico, according to his social media posts.
A week of terrorism
In the wake of the wave of multiple suspected bombs that were mailed to Democratic party leaders, CNN and Soros, prominent Trump supporters such as Lou Dobbs, Anne Coulter and Rush Limbaugh all made comments which essentially disputed the notion that such a terrorist incident could have come from the right.
They were immediately proved wrong Friday with the arrest of a Florida man, who plastered his van with stickers backing Donald Trump and assailing Democrats.
And that narrative was emphatically put to rest with the tragic attack on Saturday.
This past week, racist violence in the United States claimed the lives of two African-Americans in a Kroger store in the Louisville area on Wednesday by alleged shooter Gregory A. Bush Sr., 51.
Bush, who is white, had a history of making racist threats and he had tried unsuccessfully to gain entry to a predominantly black church just minutes before the Kroger shooting, according to local police.
The terrorist attacks in Pittsburgh and Louisville bring the total number of deaths perpetrated by far-right extremists in the United States since 9/11 to 86 people, according to New America, a research institution that tracks political violence. Meanwhile, jihadist terrorists have killed 104 during the same time period, according to the same research.
Taking the threat seriously
After 9/11, America went on a war footing and instituted a huge number of expensive measures to protect the homeland from the jihadist threat. But now that we see the horrors of domestic terrorism play out, are there things which should be done to take this threat more seriously?
A spokesman for the FBI Agents Association told CNN's Josh Campbell on Saturday, "It is time to treat domestic terrorism as the national threat that it is, and track, analyze and punish political violence at the federal level. Winning the fight against domestic terrorism is not about parties or political views; it is about ending political violence." The spokesman observed that domestic terrorism is not currently a federal crime.
Making domestic terrorism a federal crime would certainly make a powerful statement that all forms of political violence are unacceptable.
A complicating factor in the United States is that the First Amendment protects all hateful speech. This is not the case in countries such as the United Kingdom, where inciting racial or religious hatred is a crime, or in Germany, where Holocaust denial is a crime.
While it is a crime for an American to provide support to a State Department-designated Foreign Terrorist Organization such as ISIS, the First Amendment allows Americans to support or be part of neo-Nazi organizations as well as leftist militant movements.
If there were to be federal statute that allowed Americans to be charged for domestic terrorism, it would have to be artfully constructed so that it doesn't end up criminalizing protected speech, only violent conduct.