As we mark the 14th anniversary of the Sept. 11 attacks on the World Trade Center and Pentagon, it is remarkable how much has changed in the world and, yet, how much remains the same.

While there has not been a subsequent terrorist attack in the U.S., extremist Muslim factions are as deadly as ever and their murderous reach is spreading. Perhaps this is the greatest tragedy of America’s post 9/11 invasion of Iraq. Because it was based on false claims and lasted much longer than Americans were led to believe it would, we are now weary — and wary — of international intervention.

Further, the U.S. invasion — and its detention facilities — have bred a new generation of radicals. The Islamic State, or ISIS, continues its reign of terror over the Middle East. It controls territory stretching from Fallujah in Iraq to Aleppo in Syria. The group gained the international spotlight for its brutal beheadings, many of which were broadcast worldwide. It has also destroyed historic temples and beheaded scholars.

U.S.-led airstrikes and a limited number of ground troops have stopped some ISIS advances, but the militants continue to spread misery, especially in Syria, where ISIS joined a civil war in 2013.

Entire cities have been flattened amid sectarian violence there, forcing millions of refugees, half of them children, to flee to camps in Turkey, Jordan, Lebanon and Iraq. More than 7 million Syrians remain displaced in the country. Thousands have continued westward to Europe. Photos of 3-year-old Aylan Kurdi, drowned and face down on a beach in Turkey after the raft his family and others were on capsized, spurred an international conversation about the plight of Syrian refugees. His mother and 5-year-old brother also drowned while attempting to cross to Greece. The family hoped to join relatives in Canada.

Today, lawmakers face the same questions that vexed them in the wake of 9/11. What is the role of the U.S. in the world? Is it to spread democracy, as was the mantra of the Bush administration? Is it to halt the growing reach of ISIS? To protect innocent civilians from murderous thugs, terrorists and regimes? Or is it unrealistic to expect a single nation to confront these global problems?

Are any of these goals achievable? At what cost, in terms of money and human lives? Are Americans willing to bear these costs? As we’ve seen with the long U.S. involvement in Iraq and Afghanistan, even extended on-the-ground operations often end without success and at great cost to the U.S. — especially military families.

ISIS and similarly minded groups elsewhere must be confronted. That responsibility must be borne by moderate forces within the Middle East and by other nations. The U.S. likely has a role to play, but it must be clearly defined, appropriately supported and limited in duration.

The BDN Editorial Board

The Bangor Daily News editorial board members are Publisher Richard J. Warren, Editorial Page Editor Susan Young, Assistant Editorial Page Editor Matt Junker and BDN President Todd Benoit. Young has worked...