ARLINGTON, VIRGINIA – SEPTEMBER 11: President Joe Biden and First Lady Jill Biden attend a wreath-laying ceremony at the National 9/11 Pentagon Memorial on September 11, 2021 in Arlington, Virginia. The nation is marking the 20th anniversary of the terror attacks of September 11, 2001, when the terrorist group al-Qaeda flew hijacked airplanes into the World Trade Center, Shanksville, PA and the Pentagon, killing nearly 3,000 people. Kevin Dietsch/Getty Images/AFP (Photo by Kevin Dietsch / GETTY IMAGES NORTH AMERICA / Getty Images via AFP)