Is the range of Soviet SS-23 nuclear missiles short or shorter?

I can not understand how anybody can be confused by the current NATO-Soviet acrimony over nuclear missiles modernization. The USSR wants to exclude SS-23 from INF Treaty limitations. NATO opposes this.

The INF treaty covers medium- (1000-5000km range) and shorter-range (500-1000km) missiles. Short-range missiles (range between 0 and 500 km) are not included.

The Soviet SS-23 has a 480 km range, so its range is shorter than "shorter-range" missiles but the West has argued that it is not short enough to be in the short-range category. This is because in negotiating the INF treaty the Soviets had agreed that the short-range SS-23 had in fact a shorter range, not a short-range, and this placed it in a category of missiles with longer (ie "shorter") ranges than that it should actually belong to.

How could it be clearer?

:-)