A phone is pictured in a top secret historic Danish nuclear bunker, that has been opened to the public for the first time, is seen near Oplev, Denmark, February 27, 2023. REUTERS/Tom Little 

The entrance to a top secret historic Danish nuclear bunker, that has been opened to the public for the first time, is seen near Oplev, Denmark, February 27, 2023. REUTERS/Tom Little 

Helmets and rubber boots are pictured in a top secret historic Danish nuclear bunker, that has been opened to the public for the first time, is seen near Oplev, Denmark, February 27, 2023. REUTERS/Tom Little 

The doctors room of a top secret historic Danish nuclear bunker, that has been opened to the public for the first time, is seen near Oplev, Denmark, February 27, 2023. REUTERS/Tom Little 

A corridor is pictured inside a top secret historic Danish nuclear bunker, that has been opened to the public for the first time, is seen near Oplev, Denmark, February 27, 2023. REUTERS/Tom Little 

A sign is pictured inside a top secret historic Danish nuclear bunker, that has been opened to the public for the first time, near Oplev, Denmark, February 27, 2023. REUTERS/Tom Little 

A technical room of a top secret historic Danish nuclear bunker, that has been opened to the public for the first time, is seen near Oplev, Denmark, February 27, 2023. REUTERS/Tom Little 

Helmets and rubber boots are pictured in a top secret historic Danish nuclear bunker, that has been opened to the public for the first time, near Oplev, Denmark, February 27, 2023. REUTERS/Tom Little 

The lounge room of a top secret historic Danish nuclear bunker, that has been opened to the public for the first time, is seen near Oplev, Denmark, February 27, 2023. REUTERS/Tom Little 

The engine room of a top secret historic Danish nuclear bunker, that has been opened to the public for the first time, is seen near Oplev, Denmark, February 27, 2023. REUTERS/Tom Little 

The cabinet room of a top secret historic Danish nuclear bunker, that has been opened to the public for the first time, is seen near Oplev, Denmark, February 27, 2023. REUTERS/Tom Little 

The cafeteria of a top secret historic Danish nuclear bunker, that has been opened to the public for the first time, is seen near Oplev, Denmark, February 27, 2023. REUTERS/Tom Little 

A person walks inside a top secret historic Danish nuclear bunker, that has been opened to the public for the first time, near Oplev, Denmark, February 27, 2023. REUTERS/Tom Little 

A view of the entrance to a top secret historic Danish nuclear bunker, that has been opened to the public for the first time, is seen near Oplev, Denmark, February 27, 2023. REUTERS/Tom Little 

A U.S. Secret Service Agent stands watch from the shadows of the Halloween-decorted South Portico prior to the arrival of U.S. President Joe Biden and first lady Jill Biden to distribute Halloween candy to children at the White House in Washington, U.S., October 31, 2022. REUTERS/Leah Millis 

A U.S. Secret Service Agent stands watch from the shadows of the Halloween-decorted South Portico prior to the arrival of U.S. President Joe Biden and first lady Jill Biden to distribute candy to children at the White House in Washington, U.S., October 31, 2022. REUTERS/Leah Millis REFILE - UPDATING IDENTITY 

Artifacts from Iraq including playing cards of the most-wanted members of Saddam Hussein's government are on display at the newly revamped Central Intelligence Agency museum, which is revealing some newly declassified artifacts from the spy agency's most storied operations since it's founding 75 years ago, at CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

The newly revamped Central Intelligence Agency museum, while still closed to the public, features a ceiling with hidden messages, at CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

A model of Al-Zawahiri compound which was used to brief U.S. President Joe Biden on the mission that killed Al Qaeda's leader Ayman al-Zawahiri, is on display at the newly revamped Central Intelligence Agency museum, which is revealing some newly declassified artifacts from the spy agency's most storied operations since it's founding 75 years ago, at CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

A replica of the tunnel that spanned West to East Berlin, jointly built by CIA and the British Secret Intelligence Service (MI-6) during the Cold War, is on display at the revamped Central Intelligence Agency museum at CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

Artifacts from Afghanistan are on display at the newly revamped Central Intelligence Agency museum at CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

Redacted documents pertaining to the 9/11 attack, are on display at the newly revamped Central Intelligence Agency museum, which is revealing some newly declassified artifacts from the spy agency's most storied operations since it's founding 75 years ago, at CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

Robert Byer, director of the Central Intelligence Agency museum, looks on during a media tour at CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

A model of Al-Zawahiri compound which was used to brief U.S. President Joe Biden on the mission that killed Al Qaeda's leader Ayman al-Zawahiri, is on display at the newly revamped Central Intelligence Agency museum, which is revealing some newly declassified artifacts from the spy agency's most storied operations since it's founding 75 years ago, at CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

A dead drop rat and other tools used in spycraft are on display at the newly revamped Central Intelligence Agency museum, at CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

A view shows the newly revamped Central Intelligence Agency museum, while still closed to the public, as it's revealing some newly declassified artifacts from the spy agency's most storied operations since it's founding 75 years ago, at CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

Artifacts from Iraq including playing cards of the most-wanted members of Saddam Hussein's government are on display at the newly revamped Central Intelligence Agency museum, which is revealing some newly declassified artifacts from the spy agency's most storied operations since it's founding 75 years ago, at CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

The seal of the Central Intelligence Agency is shown at the entrance of the CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

A model of the Abbottabad, Pakistan compound where Osama bin Laden was killed by U.S. Navy Seals, is on display at the newly revamped Central Intelligence Agency museum, which is revealing some newly declassified artifacts from the spy agency's most storied operations since it's founding 75 years ago, at CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

An AKM assault rifle that was found next to the body of Osama bin Laden the night he was killed at his compound in Pakistan by U.S. Navy Seals, a brick from the compound, an Al-Qaeda training manual and shoes worn by a Navy Seal, are on display at the revamped Central Intelligence Agency museum at CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

A model of the Abbottabad, Pakistan compound where Osama bin Laden was killed by U.S. Navy Seals, is on display at the newly revamped Central Intelligence Agency museum, which is revealing some newly declassified artifacts from the spy agency's most storied operations since it's founding 75 years ago, at CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

A view shows the newly revamped Central Intelligence Agency museum, while still closed to the public, as it's revealing some newly declassified artifacts from the spy agency's most storied operations since it's founding 75 years ago, at CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

A duffel bag belonging to Deora Bodley, who was killed on Flight 93 on September 11, 2001, was recovered from the wreckage and is now on display at the revamped Central Intelligence Agency museum at CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

A pigeon fitted with a camera is on display at the newly revamped Central Intelligence Agency museum at CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

Janelle Neises, deputy director of the Central Intelligence Agency museum, looks on during a media tour at CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

An exhibit focused on the history of Al-Qaeda leading up to 9/11, is on display at the Central Intelligence Agency museum, at CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

The newly revamped Central Intelligence Agency museum, while still closed to the public, features a ceiling with hidden messages, at CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

Top secret briefing books for U.S. President Joe Biden are on display at the revamped Central Intelligence Agency museum, while still closed to the public, at CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

Weapons associated with Saddam Hussein are on display at the newly revamped Central Intelligence Agency museum which is revealing some newly declassified artifacts from the spy agency's most storied operations since it's founding 75 years ago, at CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

A memorial to members of the Central Intelligence Agency who lost their lives in service is shown at the entrance of the CIA headquarters in McLean, Virginia, U.S., September 24, 2022. REUTERS/Evelyn Hockstein 

A U.S. Secret Service agent looks on as U.S. first lady Jill Biden speaks with Creekwood neighborhood residents following the devastation from recent tornadoes, in Bowling Green, Kentucky, U.S., January 14, 2022. REUTERS/Jonathan Cherry 

The flag of Taiwan is seen painted on Shihyu Islet in front of Xiamen, a coastal city in China, in Lieyu Township, Kinmen, Taiwan, October 19, 2021. Sitting on the front line between Taiwan and China, Kinmen is the last place where the two engaged in major fighting, in 1958 at the height of the Cold War, and where memories of war are burned into minds decades later. REUTERS/Ann Wang SEARCH "WANG KINMEN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

A mannequin of a soldier points a model gun from inside a bunker past Shihyu Islet, towards Xiamen, a coastal city in China, in Lieyu Township, Kinmen, Taiwan, October 19, 2021. Sitting on the front line between Taiwan and China, Kinmen is the last place where the two engaged in major fighting, in 1958 at the height of the Cold War, and where memories of war are burned into minds decades later. REUTERS/Ann Wang SEARCH "WANG KINMEN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES TPX IMAGES OF THE DAY 

A mannequin of a soldier aims in the direction of China at the coastal line of Lieyu Township, Kinmen, Taiwan, October 19, 2021. Sitting on the front line between Taiwan and China, Kinmen is the last place where the two engaged in major fighting, in 1958 at the height of the Cold War, and where memories of war are burned into minds decades later. REUTERS/Ann Wang SEARCH "WANG KINMEN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES TPX IMAGES OF THE DAY 

Local women gather to play the game Four Colour Cards, in the lobby of Panshan village office on Kinmen, Taiwan, October 19, 2021. REUTERS/Ann Wang SEARCH "WANG KINMEN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

An old bunker bearing the words "fight to protect the country" sinks into the sand in Lieyu Township, Kinmen, Taiwan, October 19, 2021. Sitting on the front line between Taiwan and China, Kinmen is the last place where the two engaged in major fighting, in 1958 at the height of the Cold War, and where memories of war are burned into minds decades later. REUTERS/Ann Wang SEARCH "WANG KINMEN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

A mannequin of a soldier stands inside a bunker facing Xiamen, a coastal city in China, in Lieyu Township, Kinmen, Taiwan, October 19, 2021. Sitting on the front line between Taiwan and China, Kinmen is the last place where the two engaged in major fighting, in 1958 at the height of the Cold War, and where memories of war are burned into minds decades later. REUTERS/Ann Wang SEARCH "WANG KINMEN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Dong Teng-siang, a third generation traditional lantern maker works at his home on Kinmen, Taiwan, October 19, 2021. The lanterns Dong makes are used for weddings, painted with the names of the new family and words of blessing. REUTERS/Ann Wang TPX IMAGES OF THE DAY SEARCH "WANG KINMEN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

The flag of Taiwan flies on a scooter driving through a village on Kinmen, Taiwan, October 18, 2021. Sitting on the front line between Taiwan and China, Kinmen is the last place where the two engaged in major fighting, in 1958 at the height of the Cold War, and where memories of war are burned into minds decades later. REUTERS/Ann Wang SEARCH "WANG KINMEN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Two veterans explore an old assembly hall that they visited as young men during their military service on Kinmen, Taiwan, October 18, 2021. Sitting on the front line between Taiwan and China, Kinmen is the last place where the two engaged in major fighting, in 1958 at the height of the Cold War, and where memories of war are burned into minds decades later. REUTERS/Ann Wang SEARCH "WANG KINMEN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

A butcher prepares meat at his stall at a morning market on Kinmen, Taiwan, October 19, 2021. REUTERS/Ann Wang SEARCH "WANG KINMEN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Residents use equipment in the park to exercise on Kinmen, Taiwan, October 19, 2021. Sitting on the front line between Taiwan and China, Kinmen is the last place where the two engaged in major fighting, in 1958 at the height of the Cold War, and where memories of war are burned into minds decades later. REUTERS/Ann Wang SEARCH "WANG KINMEN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

An aeroplane flies over a former military bunker towards the airport on Kinmen, Taiwan, October 18, 2021. Sitting on the front line between Taiwan and China, Kinmen is the last place where the two engaged in major fighting, in 1958 at the height of the Cold War, and where memories of war are burned into minds decades later. REUTERS/Ann Wang SEARCH "WANG KINMEN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Wu Ja-shin, 37, holds an old shell fired from China during the 1960s at his uncle's home on Kinmen, Taiwan, October 18, 2021. Regular shelling did not end until 1978, when Washington formally recognised Beijing over Taipei.  REUTERS/Ann Wang SEARCH "WANG KINMEN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

A woman prays to a wind lion guardian at a temple in Shanhou village on Kinmen, Taiwan, October 19, 2021. Sitting on the front line between Taiwan and China, Kinmen is the last place where the two engaged in major fighting, in 1958 at the height of the Cold War, and where memories of war are burned into minds decades later. REUTERS/Ann Wang SEARCH "WANG KINMEN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

An abandoned military tank sinks in the sand on Kinmen, Taiwan, October 17, 2021. Sitting on the front line between Taiwan and China, Kinmen is the last place where the two engaged in major fighting, in 1958 at the height of the Cold War, and where memories of war are burned into minds decades later. REUTERS/Ann Wang SEARCH "WANG KINMEN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

Beishan Broadcasting Wall, a propaganda loudspeaker facing China, stands on Kinmen, Taiwan, October 17, 2021. The structure was designed to broadcast songs by Taiwanese singers and speeches inviting enemy soldiers to defect. It was used until the late 1970s. REUTERS/Ann Wang SEARCH "WANG KINMEN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

A dog stands on the counter of a souvenir shop on Kinmen, Taiwan, October 17, 2021. REUTERS/Ann Wang SEARCH "WANG KINMEN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

A veteran wears a replica of his military uniform while looking out from a bunker, during an annual trip back to Kinmen, Taiwan, October 17, 2021. Sitting on the front line between Taiwan and China, Kinmen is the last place where the two engaged in major fighting, in 1958 at the height of the Cold War, and where memories of war are burned into minds decades later. REUTERS/Ann Wang SEARCH "WANG KINMEN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES 

A statue and photo of General Li Guang-Qian are seen in the temple of General Li Guang-Qian, built in memory of a regimental commander who died fighting enemies in the Battle of Guningtou, on Kinmen, Taiwan October 17, 2021. REUTERS/Ann Wang SEARCH "WANG KINMEN" FOR THIS STORY. SEARCH "WIDER IMAGE" FOR ALL STORIES