From the executive summary: "In the ten years since the enactment of the 9/11 Commission Act, the terrorist threat landscape has evolved. It has diversified and splintered to encompass numerous al Qaeda affiliates--most notably Al Qaeda in the Arabian Peninsula (AQAP)--as well as the Islamic State of Iraq and the Levant (ISIL). [...] Since the 9/11 attacks, the nature of incidents has shifted away from complex, coordinated operations carried out by trained and funded operatives against high profile targets, to attacks carried out by individuals with little to no training or support, such -as active shooter attacks, homemade improvised explosive devices, and vehicular manslaughter. Today, America is far better equipped than it was on September 11, 2001, to prepare for, prevent, and respond to acts of terrorism and other catastrophic events. The gains in preparedness are exemplified by the heroic responses to the Boston Marathon Bombings in 2013, the San Bernardino terrorist attack in December 2015, the Orlando night club mass shooting in June 2016, and the New York/New Jersey bombings in October 2016. Since 9/11, Federal investments in local preparedness and bolstering information sharing have helped deliver measurable progress in the level of security across the Nation. Still, we must stay vigilant and fully-engaged with homeland security partners to effectively address the dynamic range of threats that, in addition to traditional terrorist threats, today include cybersecurity attacks on critical infrastructure and violence by neo-Nazi, white supremacist, anti-government, and other domestic terror groups."
Committee on Homeland Security, Democrats: https://democrats-homeland.house.gov/