While the Islamic State, also known as ISIS, is on the retreat in some parts of the Middle East, its reach in the Western world remains a serious threat. A recent arrest in New Jersey shows just how vigilant the U.S. must remain.

In February, police charged Gregory Lepsky, 20, with attempting to provide material support to a known terrorist organization. Authorities said Lepsky confessed to intending to build and detonate a pressure-cooker bomb at an undetermined location in the Manhattan area of New York City.

This is the 95th Islamist-inspired terror plot or attack within the U.S. since 2001, and the second confirmed plot of 2017.

Police said they initially arrested Lipsky on Feb. 21 after a family member reported he was threatening to kill the family dog. Local police officers took him into custody at the family residence, after which he threatened to kill his mother, who was not present, police said.

During a search of Lepsky’s room, police said, they discovered a bubble-wrapped pressure cooker and a book titled “Martyrdom in Jihad Versus Suicide Bombing.” They also found the family dog—wounded, but alive.

Over the next several days, police said, Lepsky confessed that he was working for ISIS, that he had communicated with ISIS through Facebook, and that he had planned to detonate a pressure-cooker bomb someplace where people gather in large numbers in New York City.

Through Facebook, Lapsky expressed his aspiration to die as a martyr after converting to Islam, authorities said. He also noted his affinity for ISIS through direct text and Facebook messages.

During an investigation of Lepsky’s phone and internet use, the FBI said, agents found approximately 3,340 internet searches for material relating to ISIS, terrorist attacks, beheadings, and bomb-making material between Jan. 14 and Feb. 4.

Lepsky’s alleged terror plot is part of an ongoing trend of ISIS-inspired domestic terrorism. This is the 84th such plot or attack on U.S. soil with a “homegrown” element.

Indeed, ISIS remains the most significant inspirer of Islamist-inspired domestic terror, and was behind many of the 29 other plots or attacks in 2015 and 2016.

While ISIS is losing ground in the Middle East, it remains a powerful and insidious force in the realm of homegrown terror. The U.S. must remain vigilant in the face of extremists who seek to undermine free, prosperous societies such as our own.