Hammill wanted King Crimson's guitarist and bandleader Robert Fripp to play on "The Emperor In His War Room". Fripp had never played as a session musician at that point, but had enjoyed listening to "The Least We Can Do ..." and was persuaded to take part by Anthony. Jackson recalled that Fripp "set up all of his stuff, put his headphones on, and started searing away." Fripp played the guitar part twice, having never heard the track before, and a composite of both takes appears on the final recording. Fripp has subsequently introduced Anthony as "the guy who gave me my first session" at events. Fripp would collaborate again with Van der Graaf Generator on their next album, "Pawn Hearts", released the following year.