Only Carthage really threatened Rome.
“Carthage spends a combined forty-years at war with Rome in the third century, peaking at more than 160,000 men in the field, matching Rome on land and at sea, matching the Roman capability of fighting in multiple theaters simultaneously and not-infrequently defeating Roman armies. By contrast, in the second century, the Seleucids and Antigonids manage to fight Rome for just fourteen years combined (including the Fourth Macedonian War, which isn’t even an Antigonid war!), lose every major battle and never manage to put more than 80,000 soldiers or so in the field at any one time (the Antigonids don’t even get close to that).”