According to co-director Joe Russo. Speaking at the UK press conference for Captain America: Civil War, Russo explained why Iron Man feels driven to seek out Spider-Man and his particular skills to help in the fight against Captain America’s team.
“Look, there’s a certain narcissism to the character and Tony doesn’t want to lose this fight, and at the same time I think he also sees Spider-Man as the greatest living non-lethal weapon. If you’re going out to capture a bunch of people who you don’t necessarily want to hurt, you couldn’t ask for a better character than Spider-Man to take with you.
“He does show up and illustrate that Spider-Man, he knows how powerful he is. In a video we see Spider-Man stopping a car moving 40 miles an hour, where he catches it and puts it back on the ground, so I think he believes that he’s taking with him perhaps one of the most powerful characters in the Marvel universe, and I think he feels like the kid will be well-protected under his tutelage. You also find out in that sequence, when things go wrong the kid says, ‘What do I do?’ and Tony says, ‘Keep your distance, web ’em up.’ So he’s obviously mentored the kid for what’s about to go down.”
“It’s still very irresponsible,” joked fellow director Anthony Russo.
Captain America: Civil War opens in theaters May 6, 2016, followed by Doctor Strange – November 4, 2016; Guardians of the Galaxy Vol. 2 – May 5, 2017; Spider-Man: Homecoming – July 7, 2017; Thor: Ragnarok – November 3, 2017; Black Panther – February 16, 2018; Avengers: Infinity War Part 1 – May 4, 2018; Ant-Man and the Wasp – July 6, 2018; Captain Marvel – March 8, 2019; Avengers: Infinity War Part 2 – May 3, 2019; and as-yet untitled Marvel movies on July 12, 2019, and on May 1, July 10, and November 6 in 2020.