Background: John Owen Brennan (born September 22, 1955) was the Director of the Central Intelligence Agency (CIA) from March 2013 to January 2017. He served as chief counterterrorism advisor to U.S. President Barack Obama; his title was Deputy National Security Advisor for Homeland Security and Counterterrorism, and Assistant to the President. His responsibilities included overseeing plans to protect the country from terrorism and respond to natural disasters, and he met with the President daily. Previously, he advised President Obama on foreign policy and intelligence issues during the 2008 presidential campaign and transition.
Context: In late 2008, Brennan was reportedly the top choice to become the next Director of the CIA in the incoming Obama administration. However, Brennan withdrew his name from consideration because of opposition to his CIA service under President George W. Bush and past public statements he had made in support of enhanced interrogation and the transfer of terrorism suspects to countries where they might be tortured (extraordinary rendition). President Obama then appointed him to be his Deputy National Security Advisor for Homeland Security and Counterterrorism, the President's chief counterterrorism advisor and a position that did not require Senate confirmation.  In August 2009, Brennan criticized some Bush-administration anti-terror policies, saying that waterboarding had threatened national security by increasing the recruitment of terrorists and decreasing the willingness of other nations to cooperate with the U.S. He also described the Obama administration's focus as being on "extremists" and not "jihadists". He said that using the second term, which means one who is struggling for a holy goal, gives "these murderers the religious legitimacy they desperately seek" and suggests the US is at war with the religion of Islam.  In an early December 2009 interview with the Bergen Record, Brennan remarked, "the U.S. intelligence and law enforcement communities have to bat 1.000 every day. The terrorists are trying to be successful just once". At a press conference days after the failed Christmas Day bomb attack on Northwest Airlines Flight 253 by Umar Farouk Abdulmutallab, Brennan said U.S. intelligence agencies did not miss any signs that could have prevented the attempt but later said he had let the President down by underestimating a small group of Yemeni terrorists and not connecting them to the attempted bomber. Within two weeks after the incident, however, he produced a report highly critical of the performance of U.S. intelligence agencies, concluding that their focus on terrorist attempts aimed at U.S. soil was inadequate. In February 2010, he claimed on Meet the Press that he was tired of Republican lawmakers using national security issues as political footballs, and making allegations where they did not know the facts.  Brennan was present in the Situation Room in May 2011 when the United States conducted the military operation that killed Osama bin Laden. He called President Obama's decision to go forward with the mission one of the "gutsiest calls of any president in memory." In the aftermath of the operation, Brennan said that the U.S. troops in the raid had been "met with a great deal of resistance," and bin Laden had used a woman as a human shield.
Question: Did he have a hand in any historically significant counterterrorism?
Answer: Brennan was present in the Situation Room in May 2011 when the United States conducted the military operation

Problem: Background: Gilbert and Sullivan refers to the Victorian-era theatrical partnership of the dramatist W. S. Gilbert (1836-1911) and the composer Arthur Sullivan (1842-1900) and to the works they jointly created. The two men collaborated on fourteen comic operas between 1871 and 1896, of which H.M.S. Pinafore, The Pirates of Penzance and The Mikado are among the best known. Gilbert, who wrote the libretti for these operas, created fanciful "topsy-turvy" worlds where each absurdity is taken to its logical conclusion--fairies rub elbows with British lords, flirting is a capital offence, gondoliers ascend to the monarchy, and pirates emerge as noblemen who have gone astray. Sullivan, six years Gilbert's junior, composed the music, contributing memorable melodies that could convey both humour and pathos.
Context: Sullivan was born in London on 13 May 1842. His father was a military bandmaster, and by the time Arthur had reached the age of eight, he was proficient with all the instruments in the band. In school he began to compose anthems and songs. In 1856, he received the first Mendelssohn Scholarship and studied at the Royal Academy of Music and then at Leipzig, where he also took up conducting. His graduation piece, completed in 1861, was a suite of incidental music to Shakespeare's The Tempest. Revised and expanded, it was performed at the Crystal Palace in 1862 and was an immediate sensation. He began building a reputation as England's most promising young composer, composing a symphony, a concerto, and several overtures, among them the Overture di Ballo, in 1870.  His early major works for the voice included The Masque at Kenilworth (1864); an oratorio, The Prodigal Son (1869); and a dramatic cantata, On Shore and Sea (1871). He composed a ballet, L'Ile Enchantee (1864) and incidental music for a number of Shakespeare plays. Other early pieces that were praised were his Symphony in E, Concerto for Cello and Orchestra, and Overture in C (In Memoriam) (all three of which premiered in 1866). These commissions, however, were not sufficient to keep Sullivan afloat. He worked as a church organist and composed numerous hymns, popular songs, and parlour ballads.  Sullivan's first foray into comic opera was Cox and Box (1866), written with librettist F. C. Burnand for an informal gathering of friends. Public performance followed, with W. S. Gilbert (then writing dramatic criticism for the magazine Fun) saying that Sullivan's score "is, in many places, of too high a class for the grotesquely absurd plot to which it is wedded." Nonetheless, it proved highly successful, and is still regularly performed today. Sullivan and Burnand's second opera, The Contrabandista (1867) was not as successful.
Question: What was another success of his?
Answer:
The Masque at Kenilworth (1864); an oratorio, The Prodigal Son (1869); and a dramatic cantata, On Shore and Sea (1871).