He had to content himself with making war on the Nabataeans in the deserts on the left bank of the Jordan, where he could lean for support on the Jews, but yet bore off only very trifling successes.

Ultimately the adroit Jewish minister Antipater from Idumaea persuaded Aretas to purchase a guarantee for all his possessions, Damascus included, from the Roman governor for a sum of money; and this is the peace celebrated on the coins of Scaurus, where king Aretas appears--leading his camel-- as a suppliant offering the olive branch to the Roman.
Difficulty with the Parthians Far more fraught with momentous effects than these new relations of the Romans to the Armenians, Iberians, Bosporans, and Nabataeans was the proximity into which through the occupation of Syria they were brought with the Parthian state.

Complaisant as had been the demeanour of Roman diplomacy towards Phraates while the Pontic and Armenian states still subsisted, willingly as both Lucullus and Pompeius had then conceded to him the possession of the regions beyond the Euphrates,( 19) the new neighbour now sternly took up his position by the side of the Arsacids; and Phraates, if the royal art of forgetting his own faults allowed him, might well recall now the warning words of Mithradates that the Parthian by his alliance with the Occidentals against the kingdoms of kindred race paved the way first for their destruction and then for his own.
Romans and Parthians in league had brought Armenia to ruin; when it was overthrown, Rome true to her old policy now reversed the parts and favoured the humbled foe at the expense of the powerful ally.

The singular preference, which the father Tigranes experienced from Pompeius as contrasted with his son the ally and son-in-law of the Parthian king, was already part of this policy; it was a direct offence, when soon afterwards by the orders of Pompeius the younger Tigranes and his family were arrested and were not released even on Phraates interceding with the friendly general for his daughter and his son-in-law.
But Pompeius paused not here.

The province of Corduene, to which both Phraates and Tigranes laid claim, was at the command of Pompeius occupied by Roman troops for the latter, and the Parthians who were found in possession were driven beyond the frontier and pursued even as far as Arbela in Adiabene, without the government of Ctesiphon having even been previously heard (689).
Far the most suspicious circumstance however was, that the Romans seemed not at all inclined to respect the boundary of the Euphrates fixed by treaty.