A Christian mother and daughter were shot dead by an Israeli soldier on the grounds of a Catholic church in Gaza City on Saturday, the Latin Patriarchate of Jerusalem said.
To be honest, the Roman empire's favorite target was... the Roman empire. They fought more internal than external wars, especially from the 3rd century onwards.
It would depend a lot, Carthage for example absolutely was going to shoot first if Rome didn't, the Hellenistic world as well most likely, especially after Hannibal fled there after the second Punic War.