The Times, January 13, 2018
From Style Matters, A-Z
defuse/diffuse: To defuse means to disable an explosive device by removing the fuse or reduce tension in a confrontation; to diffuse (verb) means to dilute or scatter, as in ‘the sunlight was diffused through the trees’, or it can be used an adjective as in ‘the diffused sunlight’. Watch out for this, as diffuse is often wrongly used in copy when defuse is meant.