Sri Lankan army officers carry one of the two caskets of Sri Lankan UN Peacekeepers Captain H.W.D Jayawickrama and Corporal S.S Wijekumara, who were killed when their convoy came under an Improvised Explosive Device attack in Mali, at the parade during the handover ceremony at Bandaranaike International Airport in Katunayake, Sri Lanka February 4, 2019. REUTERS/Dinuka Liyanawatte 

Sri Lankan army officers carry one of the two caskets of Sri Lankan UN Peacekeepers Captain H.W.D Jayawickrama and Corporal S.S Wijekumara, who were killed when their convoy came under an Improvised Explosive Device attack in Mali, at the parade during the handover ceremony at Bandaranaike International Airport in Katunayake, Sri Lanka February 4, 2019. REUTERS/Dinuka Liyanawatte 

Captain Adnan Abu Faisal, head of Syrian opposition's Manbij Military Council in exile, is pictured in Kafr Jana village, north of Afrin, Syria December 31, 2018. Picture taken December 31, 2018. REUTERS/Khalil Ashawi 

A U.S sailor cleans the main windscreen of the captain's bridge onboard the USS John C. Stennis as it makes its way to the Gulf through the Strait of Hormuz, December 21, 2018. REUTERS/Hamad I Mohammed TPX IMAGES OF THE DAY 

A U.S sailor cleans the main windscreen of the captain's bridge onboard the USS John C. Stennis as it makes its way to the Gulf through the Strait of Hormuz, December 21, 2018. REUTERS/Hamad I Mohammed TPX IMAGES OF THE DAY 

A U.S sailor keeps watch from the captain's bridge onboard the USS John C. Stennis as it makes its way to the Gulf through the Strait of Hormuz, December 21, 2018. REUTERS/Hamad I Mohammed 

A U.S sailor keeps watch from the captain's bridge onboard the USS John C. Stennis as it makes its way to the Gulf through the Strait of Hormuz, December 21, 2018. REUTERS/Hamad I Mohammed 

A U.S sailor cleans the main windscreen of the captain's bridge onboard the USS John C. Stennis as it makes its way to the Gulf through the Strait of Hormuz, December 21, 2018. REUTERS/Hamad I Mohammed 

Britain's Prince Harry is introduced to descendants of two England captains who died in the First World War, Jack Davis (with his grandfather Richard Slocock) who is the great, great grandson of Lancelot Slocock, and Max Garnett (with his father James) who is the great, great nephew of Ronnie Poulton, before the England v New Zealand rugby match at Twickenham Stadium, in London, Britain November 10, 2018. REUTERS/Dylan Martinez/Pool 

Britain's Prince Harry talks with Lewis Moody, former captain of English national rugby union team before the England v New Zealand rugby match at Twickenham Stadium, in London, Britain November 10, 2018. REUTERS/Dylan Martinez/Pool 

German navy Captain Sven Beck poses for a picture in Turku, Finland October 26, 2018. REUTERS/Sabine Siebold 

German navy Captain Sven Beck poses for a picture in Turku, Finland October 26, 2018. REUTERS/Sabine Siebold 

German navy Captain Sven Beck poses for a picture in Turku, Finland October 26, 2018. REUTERS/Sabine Siebold 

Brazil's far-right presidential candidate Jair Bolsonaro, a former Army captain, has surrounded himself with retired military generals. These ex-soldiers are key advisors and will serve in his cabinet if he is elected. 

U.S. President Donald Trump poses with Coach Jeff Monken (L) and team captains John Voit and Ahmad Bradshaw, with a gift for the president from the team, during the ceremony wherein Trump presented the Commander-in-Chief's Trophy to the U.S. Military Academy football team in the Rose Garden at the White House in Washington, U.S., May 1, 2018. REUTERS/Leah Millis 

French President Emmanuel Macron (2ndR), his personal military Chief of Staff, Admiral Bernard Rogel (L), the Chief of the Defense Staff of the French Army, General Francois Lecointre (2ndL) listen to Jean Porcher, ship's Captain of the Dixmude, docked in the French Navy base of Toulon, southern France, after delivering a speech to present his New Year's wishes to the French Army, January 19, 2018. REUTERS/Claude Paris/Pool 

First Captain of West Point's Corps of Cadets presents Former U.S. President George W. Bush with a Cadets' Sword as he is honored with the Sylvanus Thayer Award at the United States Military Academy in West Point, New York, U.S., October 19, 2017. REUTERS/Brendan McDermid TPX IMAGES OF THE DAY 

First Captain of West Point's Corps of Cadets presents Former U.S. President George W. Bush with a Cadets' Sword as he is honored with the Sylvanus Thayer Award at the United States Military Academy in West Point, New York, U.S., October 19, 2017. REUTERS/Brendan McDermid 

First Captain of West Point's Corps of Cadets presents Former U.S. President George W. Bush with a Cadets' Sword as he is honored with the Sylvanus Thayer Award at the United States Military Academy in West Point, New York, U.S., October 19, 2017. REUTERS/Brendan McDermid 

First Captain of West Point's Corps of Cadets presents Former U.S. President George W. Bush with a Cadets' Sword as he is honored with the Sylvanus Thayer Award at the United States Military Academy in West Point, New York, U.S., October 19, 2017. REUTERS/Brendan McDermid 

U.S. Army Captain Murzban Morris of the Department of Defense Joint Staff (R) addresses next to U.S. Ambassador Robert Wood about the North Korea's threat during the Conference on Disarmament at the United Nations Office in Geneva, Switzerland August 30, 2017. REUTERS/Denis Balibouse 

A slide showing the U.S. response to North Korea's threat is pictured during the presentation by U.S. Army Captain Murzban Morris of the Departement of Defense Joint Staff at the Conference on Disarmament at the United Nations Office in Geneva, Switzerland August 30, 2017. REUTERS/Denis Balibouse 

U.S. Ambassador Robert Wood (R) talks with U.S. Army Captain Murzban Morris of the Departement of Defense Joint Staff before their address on North Korea to the Conference on Disarmament at the United Nations Office in Geneva, Switzerland August 30, 2017. REUTERS/Denis Balibouse 

U.S. Ambassador Robert Wood (R) waits next to U.S. Army Captain Murzban Morris of the Departement of Defense Joint Staff before their address on North Korea to the Conference on Disarmament at the United Nations Office in Geneva, Switzerland August 30, 2017. REUTERS/Denis Balibouse 

Captain Megan Couto of the 2nd Battalion, Princess Patricia's Canadian Light Infantry (PPCLI), makes history as she becomes the first female infantry officer to command the Queen's Guard at Buckingham Palace, London, Britain June 26, 2017. REUTERS/John Stillwell/Pool 

Captain Megan Couto of the 2nd Battalion, Princess Patricia's Canadian Light Infantry (PPCLI), makes history as she becomes the first female infantry officer to command the Queen's Guard at Buckingham Palace, London, Britain June 26, 2017. REUTERS/John Stillwell/Pool 

Captain Megan Couto (rear R) of the 2nd Battalion, Princess Patricia's Canadian Light Infantry (PPCLI), makes history as she becomes the first female infantry officer to command the Queen's Guard at Buckingham Palace, London, Britain June 26, 2017. REUTERS/John Stillwell/Pool 

A soldier stands on duty after Captain Megan Couto of the 2nd Battalion, Princess Patricia's Canadian Light Infantry (PPCLI), makes history as she becomes the first female infantry officer to command the Queen's Guard at Buckingham Palace, London, Britain June 26, 2017. REUTERS/John Stillwell/Pool 

Captain Megan Couto of the 2nd Battalion, Princess Patricia's Canadian Light Infantry (PPCLI), makes history as she becomes the first female infantry officer to command the Queen's Guard at Buckingham Palace, London, Britain June 26, 2017. REUTERS/John Stillwell/Pool 

Captain Megan Couto of the 2nd Battalion, Princess Patricia's Canadian Light Infantry (PPCLI), makes history as she becomes the first female infantry officer to command the Queen's Guard at Buckingham Palace, London, Britain June 26, 2017. REUTERS/John Stillwell/Pool 

Captain Megan Couto of the 2nd Battalion, Princess Patricia's Canadian Light Infantry (PPCLI), makes history as she becomes the first female infantry officer to command the Queen's Guard at Buckingham Palace, London, Britain June 26, 2017. REUTERS/John Stillwell/Pool 

Captain Megan Couto of the 2nd Battalion, Princess Patricia's Canadian Light Infantry (PPCLI), makes history as she becomes the first female infantry officer to command the Queen's Guard at Buckingham Palace, London, Britain June 26, 2017. REUTERS/John Stillwell/Pool 

Captain Megan Couto of the 2nd Battalion, Princess Patricia's Canadian Light Infantry (PPCLI), makes history as she becomes the first female infantry officer to command the Queen's Guard at Buckingham Palace, London, Britain June 26, 2017. REUTERS/John Stillwell/Pool 

Captain Megan Couto of the 2nd Battalion, Princess Patricia's Canadian Light Infantry (PPCLI), makes history as she becomes the first female infantry officer to command the Queen's Guard at Buckingham Palace, London, Britain June 26, 2017. REUTERS/John Stillwell/Pool 

Captain Megan Couto of the 2nd Battalion, Princess Patricia’s Canadian Light Infantry, poses for a photograph at Wellington Barracks, in central London, Britain June 26, 2017. Couto will make history today when she commands the Queen's Guard, during the Changing of the Guard ceremony, at Buckingham Palace, and becomes the first female infantry officer to do so. REUTERS/Toby Melville 

Captain Megan Couto of the 2nd Battalion, Princess Patricia’s Canadian Light Infantry, poses for a photograph at Wellington Barracks, in central London, Britain June 26, 2017. Couto will make history today when she commands the Queen's Guard, during the Changing of the Guard ceremony, at Buckingham Palace, and becomes the first female infantry officer to do so. REUTERS/Toby Melville 

Captain Megan Couto of the 2nd Battalion, Princess Patricia’s Canadian Light Infantry, poses for a photograph at Wellington Barracks, in central London, Britain June 26, 2017. Couto will make history today when she commands the Queen's Guard, during the Changing of the Guard ceremony, at Buckingham Palace, and becomes the first female infantry officer to do so. REUTERS/Toby Melville 

A captain of the Iraqi Federal police makes his way at the frontline in western Mosul, Iraq June 4, 2017. REUTERS/Alkis Konstantinidis 

Graduate student and U.S. Army Captain Adam Freed speaks to Reuters at William James College of Psychology, the first in the nation to run a program focusing specifically on training military veterans to treat the mental health problems of their fellow soldiers and veterans, in Newton, Massachusetts, U.S., May 16, 2017. REUTERS/Brian Snyder 

King Philippe of Belgium (C) and Captain Neyt (R) attend a demonstration at a military camp in Rukla, Lithuania, May 4, 2017. REUTERS/Stephanie Lecocq/Pool 

Ekaterine Kvlividze, 30, a military pilot captain, poses for a photograph in front of a Georgian Air Force UH-1H helicopter in Tbilisi, Georgia, February 22, 2017. Kvlividze joined the Georgian Air Forces in 2007. "There were some difficulties at the beginning, I felt some irony, cynicism. I felt they did not appreciate me. But, thank God, during the last 10 years society has changed and nowadays a woman pilot is a normal thing." REUTERS/David Mdzinarishvili SEARCH "WOMEN WORK" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

USS Carl Vinson commanding officer Captain Douglas Verissimo speaks prior to the departure of the Vinson aircraft carrier from Naval Station North Island in Coronado, California, U.S. January 5, 2017. REUTERS/Mike Blake 

USS Carl Vinson commanding officer Captain Douglas Verissimo speaks prior to the departure of the Vinson aircraft carrier from Naval Station North Island in Coronado, California, U.S. January 5, 2017. REUTERS/Mike Blake 

Parade Marshall Captain Gary Tomlin gives a command during a Remembrance Sunday parade through Fulham in West London, Britain November 8, 2009. REUTERS/Kevin Coombs SEARCH "REMEMBRANCE WATCHING" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES. 

The grave of Army Captain Humayun Khan lies at Arlington National Cemetery in Arlington, Virginia, U.S., August 1, 2016. REUTERS/Joshua Roberts TPX IMAGES OF THE DAY

The grave of Captain Mehmet Karabekir (R), one of the perpetrators who died in the failed military coup, pictured at the "Traitors' Cemetery", set up specifically for coup plotters who participated July 15 abortive putsch, in Istanbul, Turkey, July 29, 2016. REUTERS/Osman Orsal 

Retired U.S. Army Captain and Medal of Honor recipient Florent "Flo" Groberg speaks during the final night of the Democratic National Convention in Philadelphia, Pennsylvania, U.S. July 28, 2016. REUTERS/Mike Segar 

Retired U.S. Army Captain and Medal of Honor recipient Florent "Flo" Groberg speaks during the final night of the Democratic National Convention in Philadelphia, Pennsylvania, U.S. July 28, 2016. REUTERS/Mike Segar 

Chinese PLA Navy officers Lt. Commander Liu Xiaomei (L), Captain Wan Lin (center left), Commander Sun Hongbin (center right), and Chief Petty Officer Qian Xiaoming answer reporters' questions aboard the PLAN replenishment ship Gaoyouhu at Joint Base Pearl Harbor Hickam while they are there to participate in the multi-national military exercise RIMPAC in Honolulu, Hawaii, July 8, 2016. REUTERS/Hugh Gentry

Chinese PLA Navy officers Lt. Commander Liu Xiaomei (L), Captain Wan Lin (center left), Commander Sun Hongbin (center right), and Chief Petty Officer Qian Xiaoming answer reporters questions aboard the PLAN replenishment ship Gaoyouhu at Joint Base Pearl Harbor Hickam while they are there to participate in the multi-national military exercise RIMPAC in Honolulu, Hawaii, July 8, 2016. REUTERS/Hugh Gentry

Chinese PLA Navy officer Captain Wan Lin listens to a reporter's question aboard the PLAN replenishment ship Gaoyouhu at Joint Base Pearl Harbor Hickam while he is there to participate in the multi-national military exercise RIMPAC in Honolulu, Hawaii, July 8, 2016. REUTERS/Hugh Gentry

United States Air Force Captain Dan DeRusha looks over his shoulder while flying a KC-10 refueling tanker on a mission to escort several F-35A fighters after taking off from McGuire Air Force Base in Wrightstown, New Jersey, June 30, 2016. REUTERS/Lucas Jackson

United States Air Force Captains Dan DeRusha (L) and Brad McElvain (C) prepare with Staff Sergeant John Loera (R) abroad a KC-10 refueling tanker on a mission to escort several F-35A fighters over the Atlantic Ocean at McGuire Air Force Base in Wrightstown, New Jersey, June 30, 2016. REUTERS/Lucas Jackson

A Captain America action figure is seen on board the USS Harry S. Truman aircraft carrier in the eastern Mediterranean Sea, June 14, 2016. REUTERS/Baz Ratner SEARCH "USS HARRY S. TRUMAN" FOR THIS STORY. SEARCH "THE WIDER IMAGE" FOR ALL STORIES 

US Defense Secretary Ash Carter (C) speaks with Gabrielle Fong, shortly after her commissioning as a naval officer at Yale University, New Haven, Connecticut, US May 23, 2016. Captain Vernon Kemper, commanding officer of the Yale Navy ROTC unit, is on the left. REUTERS/Yeganeh Torbati 

The captain of the Swiss guards marches before the start of the Easter mass led by Pope Francis in St. Peter's Square at the Vatican March 27, 2016. REUTERS/Max Rossi 

Jordanian soldiers attend the funeral of Jordanian Captain Rashed Zyoud, who was killed during a raid in Irbid conducted by the Jordanian security forces on Islamic State militants, in Zarqa, Jordan, March 2, 2016. REUTERS/Muhammad Hamed 

Jordan's King Abdullah attends the funeral of Captain Rashed Zyoud, who was killed during a raid conducted in Irbid by Jordanian security forces on Islamic State militants, in Zarqa, Jordan, March 2, 2016. REUTERS/Muhammad Hamed 

Jordanian soldiers attend the funeral of Jordanian Captain Rashed Zyoud, who was killed during a raid in Irbid conducted by the Jordanian security forces on Islamic State militants, in Zarqa, Jordan, March 2, 2016. REUTERS/Muhammad Hamed 

Jordan's King Abdullah leaves after attending the funeral of Captain Rashed Zyoud, who was killed during a raid conducted in Irbid by Jordanian security forces on Islamic State militants, in Zarqa, Jordan, March 2, 2016. REUTERS/Muhammad Hamed