Due to the typical high atmospheric noise and low transparency, submillimeter observations can be carried out only from sites with very high atmospheric stability and very low precipitable water vapour content. The Antarctic Plateau is important because of its remarkable atmospheric transparency and stability. Logistical difficulties have limited till now the exploitation of the unprecendented potential of Antarctica as a site for submillimeter observations. The opening of Concordia Station at Dome C is now offering to the international astronomical community a unique opportunity to perform ground-breaking astronomical science. The proposal from our multi-national group represents a first step toward the realization of an international Antarctic Submillimeter Observatory (ASO) based on a telescope with a large collecting area (12 m diameter) to carry out both continuum and spectral line observations, particularly in the 200 and 225 μm atmospheric windows and possibly also in the Mid InfraRed at wavelengths ≳40 μm.