Yemenis gather next to the destroyed bus at the site of a Saudi-led coalition air strike, that targeted the Dahyan market the previous day in the Huthi rebels' stronghold province of Saada on August 10, 2018. (STRINGER/AFP/Getty Images)
Buttons of possible 2020 presidential contenders, including U.S. Sen. Bernie Sanders (I-VT), Sen. Elizabeth Warren (D-MA), Sen. Cory Booker (D-NJ), Sen. Kirsten Gillibrand (D-NY), Sen. Kamala Harris (D-CA), New York State Gov. Chris Cuomo and former Vice President Joseph Biden, are seen during CPAC 2018 February 22, 2018 in National Harbor, Maryland. (Alex Wong/Getty Images)
U.S. President Donald Trump checks hands with Kim Yong Chol, former North Korean military intelligence chief and one of leader Kim Jong Un's closest aides, as Secretary of State Mike Pompeo looks on outside the Oval Office at the White House on June 1. (Olivier Douliery-Pool/Getty Images)
Donald Trump speaks to the nation, announcing military action against Syria for the recent apparent gas attack on its civilians, at the White House, on April 13, 2018. (Mike Theiler - Pool/Getty Images)
U.S. Defense Chariman Jim Mattis and Chairman of the Joint Chiefs of Staff Joseph Dunford attend a ceremony to commemorate the September 11, 2001 terrorist attacks at the Pentagon September 11, 2017 in Washington, D.C.
(Andrew Harrer-Pool/Getty Images)
U.S. Army soldiers salute during an anniversary ceremony of the 9/11 terrorist attacks on Sept. 11, 2011 at Bagram Air Field, Afghanistan. (John Moore/Getty Images)
This picture from North Korea's official Korean Central News Agency (KCNA) released on Aug. 30 shows North Korea's intermediate-range strategic ballistic rocket Hwasong-12 lifting off at an undisclosed location near Pyongyang. (STR/AFP/Getty Images)
Exclusive - Chelsea Manning attends A Becoming Resemblance exhibition by Heather Dewey-Hagborg and transgender U.S. Army intelligence officer Chelsea Manning investigating 'emerging technologies of genomic identity construction and our societal moment' opening, led by the installation 'Probably Chelsea'. The artwork comprises 30 3-D printed portraits of Manning created using DNA from cheek swabs and hair clippings mailed out of prison while she served seven years of a 35-year sentence for releasing classified and sensitive military records to WikiLeaks. Formerly known as Bradley Manning, Chelsea announced her gender transition the day after she was sentenced and began hormone replacement therapy shortly after. New York City, NY, USA, August 2, 2017. Photo by Dennis Van Tine/Sipa USA(Sipa via AP Images)
WASHINGTON, DC - SEPTEMBER 11: U.S. Defense Secretary Jim Mattis speaks at a ceremony to commemorate the September 11, 2001 terrorist attacks at the Pentagon September 11, 2017 in Washington, D.C. U.S. President Donald Trump was presiding over his first 9/11 commemoration on the 16th anniversary of the terrorist attacks that killed nearly 3,000 people when hijackers flew commercial airplanes into New York's World Trade Center, the Pentagon and a field near Shanksville, Pennsylvania. (Photo by Andrew Harrer-Pool/Getty Images)
CHARLESTON, SC - FEBRUARY 22: Reality TV host and New York real estate mogul Donald Trump holds up a replica flintlock rifle awarded him by cadets during the Republican Society Patriot Dinner at the Citadel Military College on February 22, 2015 in Charleston, South Carolina. Trump and U.S. Sen. Tim Scott (R-SC) were honored at the annual event. (Photo by Richard Ellis/Getty Images)