common enemy
- adversaryEnemy in conflict
- foeHostile opponent
- rivalOne who competes against
- threatIndication of potential harm
- nemesisPersistent source of ruin
antagonist · opposition · united · alliance · scapegoat · villain · mutual · hatred · shared · target · outsider · invasion · hostility · wartime · coalition · bonding · solidarity · truce
divisiveness
common enemywedge issue
Polarizing political subject
point of contention · bone of contention · internal conflict · apple of discord