Julian II (the Apostate) and his policies

[TITVS SABATINVS AQVILIVS]

The main point is that Julian's Persian campaign was pretty pointless from a strategic point of view and led to a vast waste of resources - it wasn't prudent at all.

If he'd been prudent he'd have continued to follow Constantius' policy for the Persian frontier - unglamorous but more or less successful.

Too simplistic, don't you think? It's like you, telling about the IIWW just say: "Well, Hitler attacked, so the Allies counterattacked and won...".

Let's ask Ammianus if the Constantius' policy was so effective:

Ammianus, XXI-16-15. But as in his foreign wars this emperor was unsuccessful and unfortunate, on the other hand in his civil contests he was successful; and in all those domestic calamities he covered himself with the horrid blood of the enemies of the republic and of himself; and yielding to his elation at these triumphs in a way neither right nor usual, he erected at a vast expense triumphal arches in Gaul and the two Pannonias, to record his triumphs over his own provinces; engraving on them the titles of his exploits ... as long as they should last, to those who read the inscriptions.

A policy based upon continuous containments and compromises was far to be a lasting solution with the Persians, more than with the great migrations people in Europe.
In his design of the roman State how Iulianus imagined to create, so aimed at perfection, any compromise policy had to be just a purely pragmatic decision to obtain further advantages in a limited and episodic context, and Iulianus was able to be clever when necessary in that sense, anyway his general and large scale policy/strategy did not provide for it of course, or rather, he found it repugnant, impure.
A flaw for a roman Emperor? Not necessarily with people like the Persians, so proudly irreducible for centuries. Anyone of us knows that the only way to eliminate forever (or almost) any danger for the roman frontier in that part of the Empire was the total elimination (not assimilation) of any persian royal dinasty and noblesmen class layer, and Iulianus killed really a lot of them and was killing them till his death.

Vale,