Episodes In Roman-Ptolemaic Relations

Maki

Ad Honorem
Jan 2017
3,975
Republika Srpska
Rome may not have been ready for war in 168, just as they weren't ready for Hannibal in 220 when he told their envoys he'd attack Saguntum and cross the Ebro (or in 219 when he besieged Saguntum for eight months and received no military opposition from Rome), just as they weren't ready for Philip V when he sided with Hannibal in 215, but attacking Rome's friends necessitated war, whether it happened sooner or later. And to judge from other Hellenistic-Roman wars it would probably have ended after one or two Roman victories and a treaty that favoured Rome. The Hellenistic kings do not appear to have shared that intense Roman drive for victory at all costs.
Sure, Rome might have come for Antiochos eventually, but I don't think he would have neccessarily faced an immediate war with Rome had he refused Popillius Laenas.
 

Maki

Ad Honorem
Jan 2017
3,975
Republika Srpska
It does seem Antiochos was afraid of Rome though. Livy tells us that Perseus of Macedon sent both Antiochos and Eumenes of Pergamon offers of alliance, specifically to oppose Rome. But from what we know Antiochos refused this.
 
Sep 2019
187
Vergina
We can also ponder a similar question with Ptolemy VI. As the Josephus quote mentioned he declined the kingship of Asia out of fear of upsetting Rome. It looks like Roman policy was to keep the balance of power in the East and deny Seleucid/Ptolemaic from gaining a total victory over the other.