Colorado Gov. John Hickenlooper shows off his socks--one with Democratic presidential candidate Bernie Sanders and the other with Republican candidate Donald Trump – before entering his former brewpub for a book signing event to mark the release of his autobiography Thursday, May 26, 2016, in Denver. Hickenlooper, who is term-limited, is doing book talk rounds this week, reviving speculation that he is positioning himself to join Hillary Clinton's presidential campaign ticket. (Photo by David Zalubowski/AP Photo)

Fighters of the Free Syrian Army fire an anti-aircraft weapon in the rebel-held Mashhad area in southeastern Aleppo, on December 12, 2016, as they battle Syrian government forces during an operation to retake the embattled city. The crucial battle for Aleppo entered its “final phase” after Syrian rebels retreated into a small pocket of their former bastion in the face of new army advances. The retreat leaves opposition fighters confined to just a handful of neighbourhoods in southeast Aleppo, the largest of them Sukkari and Mashhad. (Photo by AFP Photo/Stringer)

A scene showing one of the first trench battles is prepared for the opening of the 3D Panorama exhibition “Memory talks. The road through war” in the former Sevcabel port in St. Petersburg, Russia, 16 September 2019. Various 3D dioramas – containing genuine wartime items such as aircraft, tanks and artillery in original size – allow visitors to walk through scenes from the beginning to the end of WWII without any museum barriers. The exhibition opens from 19 September 2019 to May 2020. (Photo by Anatoly Maltsev/EPA/EFE)

Members of the Baby Dolls, a traditional Mardi Gras social club, dance during a second line parade honoring music legend Fats Domino, in New Orleans, Wednesday, November 1, 2017. The thousand-strong group marched and danced from Vaughn's Lounge to Domino's former home in the Lower 9th Ward. Domino, a New Orleans native, died this past week. (Photo by Gerald Herbert/AP Photo)

Nikolai Vasilyev, 64, dressed as Father Frost, the Russian equivalent of Santa Claus, water-skis along the Yenisei River outside the Siberian city of Krasnoyarsk, Russia December 19, 2017. Vasilyev, former teacher of the Siberian State Aerospace University, constructed the water skis out of plastic foam and designed the sticks to propel him forward, while travelling on the water surface. (Photo by Ilya Naymushin/Reuters)

Nina Bahinskaya, 73, poses for a photo holding an old Belarusian national flag at an entrance of her apartment building in Minsk, Belarus, Thursday, September 10, 2020. The 73-year-old former geologist has become one of the most recognizable faces of Belarus protests, fearlessly waving a huge opposition's red-and-white flag in front of riot police. (Photo by AP Photo/Stringer)

Supporters of former Haitian President Jean-Bertrand Aristide dance and drum as they wait near the airport for his expected arrival from Cuba, where he underwent medical treatment, in Port-au-Prince, Haiti, Friday, July 16, 2021. Aristide's return adds a potentially volatile element to an already tense situation in a country facing a power vacuum following the July 7 assassination of President Jovenel Moïse. (Photo by Fernando Llano/AP Photo)

A Hezbollah supporter fires a rocket-propelled grenade in the air to celebrate the arrival of Iranian fuel tankers to Lebanon, in the eastern town of Baalbek, Lebanon, Thursday, September 16, 2021. The delivery violates US sanctions imposed on Tehran after former President Donald Trump pulled America out of a nuclear deal between Iran and world powers three years ago. (Photo by Bilal Hussein/AP Photo)