The United States is facing an increasing, evolving national security threat from terrorists both domestic and foreign, according to homeland security analysts, who predicted more attacks as military forces proactively work to eliminate organizations such as the Islamic State.

“The threat we face now is more diverse, unpredictable, and opportunistic than ever,’’ Lisa O. Monaco, the assistant to President Obama for Homeland Security and Counterterrorism, said during a presentation at MIT in Cambridge.

Monaco was a keynote speaker at the start of a two-day National Security Conference that was sponsored by the US Attorney’s office in Boston. The list of speakers includes local and national law enforcement officers and terrorism experts, as well as those who provided firsthand accounts of the effects of the war against terrorists: the parents of men who carried out or tried to carry out attacks in the name of Islam.

“I have nothing against the religion, just the people who twisted the religion to my son,’’ said Melvin Bledsoe, whose son Carlos Bledsoe — he later called himself Abdulhakim Mujahid Muhammad — was sentenced to life in prison for shooting two Army soldiers in Arkansas in 2009.

“He was very impressionable, vulnerable, and I feel he was led down the wrong path,’’ Bledsoe said.

The conference comes as the federal court here has seen a recent string of terrorism prosecutions, and as the country considers how to deradicalize extremists. Last week, a Rhode Island man pleaded guilty in federal court in Boston to charges that he conspired to support the Islamic State, and he faces more than 15 years in prison.

The man, Nicholas Rovinski, has since disavowed his beliefs, his lawyer said. A codefendant is awaiting trial on similar charges. A man from Western Massachusetts, Alexander Ciccolo, also faces federal charges that he conspired to support the Islamic State.

In recent years, two local men were convicted of conspiring to support Al Qaeda and were sentenced to more than 17½ years in prison. And last year, Dzhokhar Tsarnaev was condemned to death by a federal jury in Boston for his role in the Boston Marathon bombing, which he later attributed to his support of Al Qaeda.

In a workshop Wednesday morning titled “Is This the New Normal,’’ security analysts said that the work of terrorists has evolved significantly since terrorists crashed two planes into the World Trade Center in 2001.

“Terrorism is a constantly evolving thing; it’s not a static threat,’’ said Michael B. Steinbach, executive assistant director of the National Security Branch of the FBI.

He and other panelists agreed that US military efforts were successful in dismantling the structure of Al Qaeda. But in its place, the Islamic State terrorist group has emerged as a regional threat in the Middle East that has used social media to spread its propaganda to supporters there and throughout the West.

Unlike Al Qaeda, which worked to coordinate large-scale attacks on symbolic targets, the Islamic State encourages supporters to attack anything, anywhere. The group was allegedly the inspiration for the recent stabbing of 10 people at a mall in Minneapolis, the killing of nearly 50 people at a Florida nightclub in June, and an attack in Nice, France, in which a truck was driven into a crowd of people, the analysts said.

“These are somewhat more frightening to people because they feel they could be attacked anywhere,’’ said Jessica Stern, a research professor at the Pardee School of Global Studies at Boston University. “We’ve seen how deadly these attacks can be.’’

Several panelists sought to put terrorism in the context of other crimes, saying far more people in the United States die of gun violence or car accidents than as the result of a terrorist attack. Last year, according to Steinbach, 19 Americans died in terrorist attacks in the United States and 21 died abroad.

“We need to put terrorism in context; it’s not this big scary monster,’’ he said.

But he and others agreed that the threat of the Islamic State and the attacks the group inspires remain an evolving concern for law enforcement. Monaco, the assistant to the president, criticized the “is this the new normal?’’ way of thinking, a reference to the name of the workshop.

She warned that we should resist accepting terrorist attacks as a fact of life, she said. “If we don’t, we have lost our way as Americans.’’

Milton J. Valencia can be reached at milton.valencia @globe.com. Follow him on Twitter @miltonvalencia.