The construction of Lorentz covariant three‐body states and their angular momentum decomposition is reviewed. It is shown how they can be used to construct the impulse approximation to the optical potential in momentum space. The potential thus constructed incorporates covariant kinematics, relativistic normalizations and phase space factors, a covariant treatment of the recoil of the target nucleus, utilizes invariant amplitudes which are free of kinematic singularities, and allows an exact performance of the fermi integration over the momentum of the struck nucleon. The interaction of the K+meson with12C and40Ca is examined and it is found that the present data indicate an enhanced, in‐medium, two‐body interaction. We find that all the data is consistent with an angle and energy independent 25% enhancement of the theoretical calculations.