Question: Who was the director of the 1968 Metrocolor Cold War era suspense and espionage film that had its screenplay written by the novelist who wrote under the pseudonym Ian Stuart?

Context paragraphs:
Alistair MacLean: Alistair Stuart MacLean (Scottish Gaelic: "Alasdair MacGill-Eain" ; 21 April 1922 – 2 February 1987) was a Scottish novelist who wrote popular thrillers and adventure stories.  His works include "The Guns of Navarone", "Ice Station Zebra" and "Where Eagles Dare" – all three were made into popular films.  He also wrote two novels under the pseudonym Ian Stuart.

Culture during the Cold War: The Cold War (1947–91) was reflected in culture through music, movies, books, television and other media, as well as sports and social beliefs and behavior.  One major element of the Cold War was the threat of a nuclear war; another was espionage.  Many works use the Cold War as a backdrop, or directly take part in fictional conflict between the United States and the Soviet Union The period 1953–62 saw Cold War themes first enter the mainstream culture as a public preoccupation.  For the historical context in America see United States in the 1950s.

Ice Station Zebra: Ice Station Zebra is a 1968 Metrocolor Cold War era suspense and espionage film directed by John Sturges, starring Rock Hudson, Patrick McGoohan, Ernest Borgnine, and Jim Brown.  The screenplay by Alistair MacLean, Douglas Heyes, Harry Julian Fink, and W. R. Burnett is loosely based upon MacLean's 1963 novel of the same name.  Both have parallels to real-life events that took place in 1959.  The film was photographed in Super Panavision 70 by Daniel L. Fapp, and presented in 70 mm Cinerama in premiere engagements.  The original music score is by Michel Legrand.

The Satan Bug: The Satan Bug is a 1965 American science fiction suspense film from United Artists, produced and directed by John Sturges, that stars George Maharis, Richard Basehart, Anne Francis and Dana Andrews.  The screenplay by James Clavell and Edward Anhalt was loosely based on the 1962 novel of the same name by Alistair MacLean under the pseudonym Ian Stuart.  The film score was composed by Jerry Goldsmith.

The Satan Bug (novel): The Satan Bug is a first-person narrative thriller novel written by Scottish author Alistair MacLean.  It was originally published in 1962 under the pseudonym Ian Stuart, and later republished under MacLean's own name.

Aftermath of World War II: The aftermath of World War II was the beginning of an era defined by the decline of the old great powers and the rise of two superpowers: the Soviet Union (USSR) and the United States of America (USA).  Allied during World War II, the USA and the USSR became competitors on the world stage and engaged in the Cold War, so called because it never resulted in overt, declared hot war between the two powers but was instead characterized by espionage, political subversion and proxy wars. Western Europe and Japan were rebuilt through the American Marshall Plan whereas Eastern Europe fell under the Soviet sphere of influence and eventually an "Iron Curtain".  Europe was divided into a US-led Western Bloc and a Soviet-led Eastern Bloc.  Internationally, alliances with the two blocs gradually shifted, with some nations trying to stay out of the Cold War through the Non-Aligned Movement.  The Cold War also saw a nuclear arms race between the two superpowers; part of the reason that the Cold War never became a "hot" war was that the Soviet Union and the United States had nuclear deterrents against each other, leading to a mutually assured destruction standoff.

The Dark Crusader: The Dark Crusader is a 1961 thriller novel by Scottish author Alistair MacLean.  The book was initially written under the pseudonym Ian Stuart and later under his true name.  It was released in the United States under the title: The Black Shrike.

Post–Cold War era: The post–Cold War era is the period in world history from the dissolution of the Soviet Union in 1991 to the present.  The term was criticized for its ambiguity: "Even though it has been ten years since the Berlin Wall came down, wrote Paul Wolfowitz in 2000, we still have no better name for the period in which we live than the "post-Cold War era"."  The name means that this new era “does not yet have a name.”  it was suggested that "Pax Americana" would more reflect the reality of the era but this term would be "offending for many."  The same dilemma expressed Condoleezza Rice: “That we do not know how to think about what follows the US-Soviet confrontation is clear from the continued references to the "post-Cold War period.'"  "We knew better where we had been than where we were going.”

West Berlin: West Berlin was a political enclave which comprised the western part of Berlin during the years of the Cold War.  There was no specific date on which the sectors of Berlin occupied by the Western Allies became "West Berlin", but 1949 is a widely accepted date.  West Berlin was formally controlled by the Western Allies and formed a "de facto" part of West Germany, even though it was entirely surrounded by the Soviet-controlled East Berlin and East Germany.  West Berlin had great symbolic significance during the Cold War, as it was widely considered by westerners as an "island of freedom".  It was heavily subsidised by West Germany as a "showcase of the West".  A wealthy city, West Berlin was noted for its distinctly liberal and cosmopolitan character, and as a centre of education, research and culture.  With about two million inhabitants, West Berlin had the biggest population of any city in Germany during the Cold War era.

Tinker Tailor Soldier Spy (film): Tinker Tailor Soldier Spy is a 2011 Cold War espionage film directed by Tomas Alfredson.  The screenplay was written by Bridget O'Connor and Peter Straughan, based on John le Carré's 1974 novel of the same name.  The film, starring Gary Oldman as George Smiley, along with Colin Firth, Tom Hardy, John Hurt, Toby Jones, Mark Strong, Benedict Cumberbatch, and Ciarán Hinds, and featuring David Dencik, is set in London in the early 1970s and follows the hunt for a Soviet double agent at the top of the British secret service.

Supporting paragraphs: Ice Station Zebra Alistair MacLean
Answer: John Sturges