S.T.R.I.K.E. began as a British version of S.H.I.E.L.D. It included a Psi-Ops division, where Betsy Braddock was initially trained in the use of her telepathic powers. S.T.R.I.K.E. was infiltrated by the crimeboss Vixen prior to the Jaspers Warp. Many of the Psi-Ops agents were killed to prevent them from uncovering this corruption. S.T.R.I.K.E. was retired and many loyal operatives were relocated to the new RCX.
Years later, the United Kingdom severed diplomatic ties with the nation of Krakoa. Peter Wisdom of MI-13 was betrayed and abandoned by factions in his country. He relocated to Krakoa and arranged resurrection protocols for many of the fallen Psi-Ops agents, reforming S.T.R.I.K.E. in connection with Krakoa.
