Question: The uncle of Paul Capellani died at a military operation during a battle was fought between who?

Context:
Operation Mersad
Operation Mersad (Persian: عملیات مرصاد‎ ‎ , meaning "ambush") was the last major military operation of the Iran–Iraq War, ending in a decisive victory for Iran.
 The operation involved a successful counterattack against a July 1988 military incursion from Iraq, by a military force of about 7,000 members of the Mujahadeen-e-Khalq (MEK).
 The MEK soldiers were armed, equipped and given air support by Iraq.
 Led by Lt. General Ali Sayad Shirazi, Operation Mersad began on 26 July 1988 and lasted only a few days, where the Iranian Armed Forces crushed the MEK in what was the last military operation of any significance of the war.
Paul Capellani
Paul Capellani (September 9, 1877 – November 7, 1960) was a noted French silent film actor.
 His brother was the director Albert Capellani and his uncle the film director Roger Capellani who died May 1940 at the Battle of Dunkirk.
Albert Capellani
Albert Capellani (23 August 1874 – 26 September 1931) was a French film director and screenwriter of the silent era.
 He directed films between 1905 and 1922.
 One of his brother was the actor-sculptor Paul Capellani.
 and another the film director Roger Capellani.
Roger la Honte (1913 film)
Roger la Honte or A Man's Shadow is a 1913 French silent historical drama film directed by Adrien Caillard and starring Georges Dorival, Paul Capellani and Henri Collen.
 It is an adaption of the novel of the same title by Jules Mary, which has been filmed a further four times since.
Battle of Dunkirk
The Battle of Dunkirk was a military operation that took place in Dunkirk (Dunkerque), France, during the Second World War.
 The battle was fought between the Allies and Nazi Germany.
 As part of the Battle of France on the Western Front, the Battle of Dunkirk was the defence and evacuation of British and Allied forces in Europe from 26 May to 4 June 1940.
Operation Balavegaya
Operation Balavegaya (Operation Power force) was a combined military operation launched by the Sri Lankan military in Jaffna, the largest amphibious assault in its history.
 Operation Balavegaya was launched in response to the siege of Elephant Pass by the LTTE.
 It is believed that Operation Balavegaya was the largest and most successful military operation of the Sri Lankan military until Operation Riviresa in 1995.
Roger Capellani
Roger Capellani (31 January 1905 – 30 May 1940) was a French film director, the son of film director and screenwriter Albert Capellani and the nephew of the actor Paul Capellani.
La Bohème (1916 film)
La Bohème (aka:La vie de Bohème) is a 1916 silent historical film directed by Albert Capellani and distributed by World Pictures.
 The star of this version is Alice Brady, whose father William A. Brady was the founder of World Pictures.
 This film is one of many silent versions, actually the third or fourth.
 Later silent versions appeared in 1917 and 1926 starring Lillian Gish.
 Director Albert Capellani's brother, Paul Capellani, who appears in this film, had made his own short version in 1912.
Camille (1915 film)
Camille is a 1915 American silent film based on the story "La Dame aux Camélias" ("The Lady of the Camellias") by Alexandre Dumas, "fils", first published in French as a novel in 1848 and as a play in 1852.
 Adapted for the screen by Frances Marion, "Camille" was directed by Albert Capellani and starred Clara Kimball Young as Camille and Paul Capellani as her lover, Armand.
Patrie (1917 film)
Patrie is a 1917 French film by Albert Capellani after the drama of Victorien Sardou.
 The film featured Henry Krauss as the Count of Rysoor, Paul Capellani as Karloo Van der Noot, Léon Bernard as Ionas, and Maxime Desjardins as the Duke of Alba.

Answer: the Allies and Nazi Germany