Start a War (song)

"Start a War" is an unreleased song recorded by American singer Gwen Stefani. Originally intended for her third studio album, the ballad was written by Stefani and Sia and produced by Arnthor Birgisson. Stefani said she was grateful for Sia's help with the composition. In the end, the song did not make the final cut of This Is What the Truth Feels Like, Stefani's third studio album released in 2016. The song was intended to serve as a bonus track on a CD maxi single for her 2014 single "Baby Don't Lie", although the distribution was scrapped by Interscope and Mad Love Records. After it was registered with a UPC, Universal Music Group announced that it would be issued as a standalone digital download on November 9, 2015, but these plans were also cancelled.

A power ballad, "Start a War" garnered praise for Stefani's vocals and Sia's role as a songwriter. Several music critics commended it as a typical Sia ballad and a good fit for Stefani. The track has only been performed once during a MasterCard Priceless Surprises Presents Gwen Stefani concert on February 7, 2015. The rendition was accompanied by a backdrop displaying falling feathers and featured Stefani dressed in a similar attire.