[The following essay contains MAJOR SPOILERS for both Avengers: Infinity War and Avengers: Endgame. Continue reading at your own risk.]
Superhero movies tend to work best when their central themes can be distilled down to a single word. The Dark Knight Rises is all about “Pain,” while Captain America: Civil War examines how its various characters react to “Loss.” Both Avengers: Endgame and its immediate prequel, Infinity War, revolve around the idea of “Sacrifice,” thoroughly exploring the prices that their respective protagonists are willing to pay in order to achieve victory—and how what they choose to give up defines them.
[Final Warning: SPOILERS BELOW!]
In the first installment of the duology, Thanos frequently mocks his opponents for what he perceives to be their lack of resolve. Indeed, the Avengers and their allies lose no less than three Infinity Stones because they’re unwilling to “trade lives” (Loki surrenders the Tesseract to save Thor; Star-Lord hesitates to shoot Gamora, inadvertently providing Thanos with the key to locating the elusive Soul Stone; Wanda refuses to risk destroying Vision along with the Mind Stone, leading directly to the team’s eventual defeat). The Mad Titan himself, on the other hand, succeeds because he does make those difficult decisions; in the end, he watches the sun rise on a “perfectly balanced” universe—and all it cost him was “everything,” including his entire army and his “favorite daughter.”
All of these sacrifices, however, feel undeniably hollow, because they’re motivated by selfish desires. Beneath Thanos’ altruistic exterior lies an arrogant, self-righteous zealot; once you've stripped away his rhetoric about “simple calculus” and “the greater good,” what remains is a bitter, angry outcast obsessed with validating his own brutality and extremism. True to this egocentric personality, he barely seems to value the things he discards over the course of his journey; his “children” are little more than expendable servants and slaves, and even his relationship with his beloved Gamora is one-sided and transparently abusive.
Fortunately, Endgame deconstructs its predecessor’s apparent message (that the merciless prosper while the compassionate suffer), revealing the core qualities that make its heroes… well, heroic. Like their nemesis, the Avengers will do "whatever it takes” to win—but for them, the sentiment carries a significantly different meaning. Consider, for example, how Black Widow and Hawkeye/Ronin respond to the Vormir Dilemma: in order to obtain the Soul Stone, the seeker must offer up a living soul in exchange. Whereas Thanos executed Gamora with only a token display of remorse, Natasha and Clint literally race to throw themselves into the abyss, each desperate to protect the other. Hawkeye’s insistence that he should be the one to perish is particularly selfless—he’s determined to ensure his family’s resurrection, even if it entails relinquishing the opportunity for a reunion. Similarly, Tony Stark adamantly maintains that his first priority is safeguarding the peaceful life he’s built with his wife and child; when he snatches the Infinity Gauntlet during the climactic showdown, knowing that he probably won’t survive his attempt to eradicate Thanos’ forces, he’s well aware of what he stands to lose—and he snaps his fingers anyway, because there’s far more at stake than just his own happiness.
That distinction, the films argue, is what truly separates the “good” guys from the “bad.” Thanos sacrifices others in the pursuit of an abstract, intangible (and very likely unattainable) goal. The Avengers, meanwhile, sacrifice their own lives in order to defend (and, in some cases, restore) their loved ones, a cause that is both more concrete and more noble than their foe’s—which is exactly why, after enduring innumerable setbacks, failures, and hardships, they finally emerge victorious, while the Mad Titan’s ruthless ambition crumbles to dust.
Before he pays the ultimate price for his heroism, Stark utters the iconic catchphrase that launched the Marvel Cinematic Universe one last time: “I am Iron Man.” Never has a snappy one-liner resonated with such indisputable truth.