In order to settle the fundamental question whether the nuclear forces involve the long range components, the S-wave amplitude of the proton-proton scattering is analysed in search for the extra singularity at $\nu=0$, which corresponds to the long range force. To facilitate the search, a function, which is free from the singularities in the neighborhood of $\nu=0$ when all the interactions are short range, is constructed. The calculation of such a function from the phase shift data reveals a sharp cusp at $\nu=0$ in contradiction to the meson theory of the nuclear force. The type of the extra singularity at $\nu=0$ is close to what is expected in the case of the strong van der Waals interaction. Physical meanings of the long range force in the nuclear force are discussed. Low energy p-p experiments to confirm directly the strong long range interaction are also proposed, in which the characteristic interference patten of the Coulonb and the Van der Waals forces is predicted.