The Syrian state embraced at the most Mesopotamia in addition to the region of the coast, and disappeared, more in consequence of its internal disorganization than of its diminished size, for ever from the ranks of the great states.

If the danger-- which was repeatedly imminent--of a total subjugation of the land by the Parthians was averted, that result must be ascribed not to the resistance of the last Seleucids and still less to the influence of Rome, but rather to the manifold internal disturbances in the Parthian empire itself, and above all to the incursions of the peoples of the Turanian steppes into its eastern provinces.
Reaction of the East against the West This revolution in the relations of the peoples in the interior of Asia is the turning-point in the history of antiquity.

The tide of national movement, which had hitherto poured from the west to the east and had found in Alexander the Great its last and highest expression, was followed by the ebb.

On the establishment of the Parthian state not only were such Hellenic elements, as may still perhaps have been preserved in Bactria and on the Indus, lost, but western Iran also relapsed into the track which had been abandoned for centuries but was not yet obliterated.

The Roman senate sacrificed the first essential result of the policy of Alexander, and thereby paved the way for that retrograde movement, whose last offshoots ended in the Alhambra of Granada and in the great Mosque of Constantinople.
So long as the country from Ragae and Persepolis to the Mediterranean obeyed the king of Antioch, the power of Rome extended to the border of the great desert; the Parthian state could never take its place among the dependencies of the Mediterranean empire, not because it was so very powerful, but because it had its centre far from the coast, in the interior of Asia.