Universal’s “Green Zone” became the latest Iraq War-themed movie to fall down the box office rabbit hole, debuting to just $5 million in the U.S. and Canada Friday, according to studio estimates. […] That would be even less than the modest pre-release expectations for the $100 million film, which reteams star Matt Damon and director Paul Greengrass, who worked on the Universal’s last two “Jason Bourne” franchise installments. The film was put into production during the co-chair term of Marc Shmuger and David Linde.