The alternative view is to see the campaign as triggered by the lure of territorial annexation and prestige,[21] the sole motive ascribed by Cassius Dio.[26] As far as territorial conquest involved tax-collecting,[27] especially of the 25% tax levied on all goods entering the Roman Empire, the tetarte, one can say that Trajan's Parthian War had an "economic" motive.[28] Also, there was the propaganda value of an Eastern conquest that would emulate, in Roman fashion, those of Alexander the Great.[29] The fact that emissaries from the Kushan Empire might have attended to the commemorative ceremonies for the Dacian War may have kindled in some Greco-Roman intellectuals like Plutarch – who wrote about only 70,000 Roman soldiers being necessary to a conquest of India – as well as in Trajan's closer associates, speculative dreams about the booty to be obtained by reproducing Macedonian Eastern conquests.[30] Also, it is possible that the attachment of Trajan to an expansionist policy was supported by a powerful circle of conservative senators from Hispania committed to a policy of imperial expansion, first among them being the all-powerful Licinius Sura.[31] One can explain the campaign by the fact that, for the Romans, their empire was in principle unlimited, and that Trajan only took advantage of an opportunity to make idea and reality coincide.[32]