CHICAGO - "Twenty years after the September 11 attacks, America is poorer, more militarized and more polarized," said Juan Cole, a professor of history at the University of Michigan (UM) who studies the ongoing political change in the Middle East.

Instead of a lean, targeted counterterrorism policy, the United States launched big, messy wars, Cole said.

"The unnecessary wars and long-term military occupations for which Washington elites made September 11 a pretext cost trillions ... running up the national debt to alarming levels," he said.

Tens of thousands of veterans suffer from war injuries or post-traumatic stress disorder and suffer high suicide rates. Police departments that received excess war material became distant from their own communities and often seemed like occupation forces themselves.

"The wars and occupations manifestly failed, diminishing US standing in the world," Cole stressed.

Adam Horwitz, an assistant professor of psychiatry at the UM, holds that Sept. 11 is unique in that it has an impact and holds meaning for all Americans. "In many ways, it is more of a 'memorial day' than the actual Memorial Day in the United States."

"Sept. 11 is an opportunity for a more somber reflection of those we lost on that day, as well as the veterans and their families who experienced losses in the subsequent wars in Afghanistan and Iraq," Horwitz said.

"The tragedy" of Sept. 11 "resuscitated a politics of fear that was directed against Arab and Muslim immigrants in the same way that the politics of fear was turned against Italian immigrants in the early 20th century, German immigrants in World War I and Japanese immigrants in World War II," said Ann Lin, associate professor of public policy at UM's Ford School of Public Policy.

"But the evidence of history, and of the past 20 years, shows that immigrants fight for the US in wars, create the technology that keeps America safe and strengthen our knowledge and understanding of other societies and nations," the professor said.

Yasmin Moll, an associate professor of anthropology from the UM, echoed Lin's words. "The narrative of a clear-cut 'us' versus a clear-cut 'them' was easy to adopt in the aftermath of September 11."

Moll said the narrative depicts Arabs and Muslims as fundamentally terrifying. "These media representations left room neither for the ordinary experiences of individual Arabs or Muslims nor for the collective trauma of Arabs and Muslims as themselves victims of political violence and terrorism, whether here in the United States or abroad."

Javed Ali, an associate professor of practice at UM's Ford School of Public Policy, holds that 20 years after Sept. 11, the United States is at an inflection point with respect to its posture against terrorism, with a shift more towards combating domestic terrorism as against international terrorism.

Unlike the immediate years following Sept. 11 and through the campaign against the Islamic State in Iraq and Syria in the mid-2010s, counterterrorism is no longer the dominant national security issue that draws an outsized level of policymaker and public attention, as well as money, resources and personnel, Ali said.

Despite a smaller focus on counterterrorism in the years ahead, "terrorism will continue to present challenges both domestically and abroad," he said.