"World on Fire" was written by Jared and Shannon Leto, with additional contributions from Steve McCutcheon, Johnny McDaid, and Ed Sheeran, of whom the first four produced the song alongside Oscar Neidhardt.

[1] Musically, "World on Fire" reinforces the heavily layered production that defined much of the band's later works.

It features a minimalist instrumentation, with clean guitars, subtle electronic elements, and a prominent vocal performance from Jared Leto.

The lyrics of the song deal with themes of uncertainty, resistance, and hope in a world facing numerous crises.

The review highlights that this track, alongside others, showcases the band's evolution, moving away from the bombastic arena rock of This Is War (2009) while still maintaining a grand feel.