Peter Bergen is CNN's national security analyst, a vice president at New America and a professor of practice at Arizona State University. He is the author of "United States of Jihad: Investigating America's Homegrown Terrorists." David Sterman is a senior policy analyst at New America. The opinions expressed in this commentary are their own. View more opinion articles at CNN.

(CNN) The Trump administration's National Counterterrorism Strategy correctly states that the country has "long faced a persistent security threat from domestic terrorists who are not motivated by a radical Islamist ideology but are instead motivated by other forms of violent extremism."

Peter Bergen

David Sterman

Saturday's attack in El Paso, Texas, which is being treated as a case of domestic terrorism by federal authorities, according to the US attorney for the Western District of Texas, is a reminder of that long history and its particular threat today.

To prevent future attacks, the United States will need to expand on the work being done by law enforcement to combat right-wing terrorism, and President Donald Trump will need to recognize that the threat posed by far-right terrorists is of a similar scope to that posed by jihadist terrorists.

Trump should also use the bully pulpit of his presidency to attack the ideological underpinnings of right-wing violence rather than stoking its flames.

On Saturday, authorities say, a 21-year-old white man shot and killed 20 people at a Walmart in El Paso, Texas. Minutes before the attack, police say, they believe the shooter posted a "manifesto " on 8chan, an online message board often featuring racist postings, about his support for the terrorist who killed 50 worshippers at two mosques in Christchurch, New Zealand, in March.