An explanation of the shrinking, nonshrinking, and expanding diffraction peaks at high energy (≳10 BeV) is given in terms of two kinds of forces: (1) due to the exchange of the π-π, J PG = 0 ++, T = 0 antibound state or virtual state, and (2) due to the exchange of the J PG = 1 −− vector meson (ω + φ). It is shown that the energy dependence of the diffraction peaks can essentially come from the vector meson exchange force, because this force falls off more slowly at high energy than the other force. Thus, for π +p and π −p scattering, as the vector meson force does not occur, we have little energy dependence or non-shrinking diffraction peaks. For pp and K +p scattering, the vector meson exchange force can have asymptotic behavior such that it decreases absorption as the energy increases and this behavior then gives shrinking diffraction peaks. For p ¯ p and K −p the vector meson exchange force changes sign and as a result, the absorption now increases as the energy increases. This behavior produces expanding diffraction peaks. The absorption (or inelasticity) at high energy has been dynamically related with the input forces, in the framework of an impact parameter formalism. The asymptotic behavior, which is found for the vector meson force, is explained in terms of a suitably constructed Mandelstam double spectral function. This explanation also indicates how the compositeness of the vector meson comes about. On the basis of unitarity argument, it is pointed out that the vector meson cannot behave as an elementary particle. The incident and the outgoing particles are treated as spinless.