Question: Which documentary was screened at Cannes, The World Without US or The Thorn in the Heart?

Context paragraphs:
Mitch Anderson (director): Mitch Anderson is a Romanian-born American film director, producer, writer, researcher and editor.  He is the only son of former political dissidents of the Stalinist era.  His first film, "The World Without US", explores what might happen if the United States were to leave the international arena, rescind its global reach and return to being a non-interventionist nation.

Just the Best Party: Just the Best Party is the second studio album by The World/Inferno Friendship Society.  It was released on April 2, 2002 on Gern Blandsten Records.  It is referred to by the band as 'Inferno #8', as it is the eighth release of new material by the band.  The first six songs on the album originally appeared on the "International Smashism! " EP and two other songs, "I Wouldn't Want to Live in a World Without Grudges" and "All the World Is a Stage (Dive)", are re-recorded versions of songs that originally appeared on the "I Wouldn't Want to Live in a World Without Grudges" single.

Center for Chilean-American Studies: Founded on September 6, 2006, the Center for Chilean-American Studies (CCAS) is an organization which seeks to promote public awareness about the presence of immigrants from Chile in North America.  As the center's founding constitution states, " Chilean-Americans bring a diverse heritage to North America."  The motto of the organization is simply "Un mundo sin Chilenos es un mundo sin corazon."  In English, this translates roughly into "A world without Chileans is a world without a heart."

The World Without Us: The World Without Us is a non-fiction book about what would happen to the natural and built environment if humans suddenly disappeared, written by American journalist Alan Weisman and published by St. Martin's Thomas Dunne Books.  It is a book-length expansion of Weisman's own February 2005 "Discover" article "Earth Without People".  Written largely as a thought experiment, it outlines, for example, how cities and houses would deteriorate, how long man-made artifacts would last, and how remaining lifeforms would evolve.  Weisman concludes that residential neighborhoods would become forests within 500 years, and that radioactive waste, bronze statues, plastics, and Mount Rushmore would be among the longest-lasting evidence of human presence on Earth.

World Without Superman: "World Without Superman" is a Superman comic book story arc published by DC Comics.  It takes place in "Action Comics" written by Greg Rucka with art by Sidney Teles and "Superman" written by James Robinson with art by Renato Guedes.  The story deals with Metropolis dealing with a world without Superman, who has gone to live on New Krypton to keep General Zod in check.  As a result, the two Superman series, Action Comics and Superman star Nightwing & Flamebird and Mon-El respectively.

It's Hard to Move You: It's Hard to Move You is the second full-length album by A Thorn for Every Heart.  The band began recording in late 2005/early 2006 with producer Matt Squire (Panic!  at the Disco, The Receiving End of Sirens).  They initially claimed to be done recording in January 2006 with a summer 2006 release date, but was sent back to the studio by the label, recording additional songs with Mark Hoppus of Blink-182.  The album was later set to be released on July 31, 2007, but was shelved when Interscope shut-down Kickball Records, leaving all Kickball projects in limbo and A Thorn For Every Heart without a label.  The album was leaked completely online on June 1st, 2007.

The World Without US: The World Without US is a documentary film created by Mitch Anderson and Jason J. Tomaric.  Released in 2008, the documentary explores what might happen if the United States were to leave the international arena, rescind its global reach and become an isolationist nation for the first time since the early 20th century.

World Without Oil: World Without Oil (WWO) is an alternate reality game (ARG) created to call attention to, spark dialogue about, plan for and engineer solutions to a possible near-future global oil shortage, post peak oil.  It was the creation of San Jose game writer and designer Ken Eklund, and ARG veterans Jane McGonigal, Dee Cook, Marie Lamb, Michelle Senderhauf, and Krystyn Wells were on the puppetmaster team.  "World Without Oil" was presented by Independent Television Service (ITVS) with funding by the Corporation for Public Broadcasting.

The Thorn in the Heart: The Thorn in the Heart (French: "L'épine dans le coeur" ) is a 2009 French documentary film directed by Michel Gondry.  It was given a special screening at the 2009 Cannes Film Festival and was also screened at the Sheffield Doc/Fest.

World Without End (miniseries): World Without End is an eight-episode 2012 television miniseries based on the novel of the same name by Ken Follett.  It is a sequel to the 2010 miniseries "The Pillars of the Earth", also based on a Follett novel.  "World Without End" is set 150 years after "The Pillars of the Earth" and chronicles the experiences of the fictional English town of Kingsbridge during the start of the Hundred Years' War and the outbreak of the Black Death.  The cast is led by Cynthia Nixon, Miranda Richardson, Ben Chaplin, Peter Firth, Charlotte Riley, and Tom Weston-Jones.  The miniseries varies significantly from the novel in both the plot and characterizations.

Supporting paragraphs: The World Without US The Thorn in the Heart
Answer: The Thorn in the Heart